Switch Statement Keeps Returning Undefined

Question

I'm fairly new to switch statements in general but please could anyone let me know why my switch statement here is returning undefined? I feel like i've looked at this code for way too long and need another set of eyes to see where i'm going wrong.

Posted the code below. Any input would be much appreciated :)

var sizingIndicator = function(){
var isMobile = document.getElementById('panel');
var addToCartSelector = $('.a');
var addToCartSelectorMob = $('.p');

     var standard_size_0 =  '0 (XS)',
        standard_size_2 =  '2 (S)',
        standard_size_4 =  '4 (S)',
        standard_size_6 =  '6 (M)',
        standard_size_8 =  '8 (M)',
        standard_size_10 = '10 (L)',       
        standard_size_12 = '12 (L)',
        standard_size_14 = '14 (XL)';

    var standard_size_0_withoutSML =  '0',
        standard_size_2_withoutSML =  '2',
        standard_size_4_withoutSML =  '4',
        standard_size_6_withoutSML =  '6',       
        standard_size_8_withoutSML =  '8',
        standard_size_10_withoutSML = '10',
        standard_size_12_withoutSML = '12',
        standard_size_14_withoutSML = '14';

    var standard_size_0_additional_info =  '<span class="header">Measurements:</span><span>Bust:<span class="value">30.9</span></span><span>Waist:<span class="value">23.8</span></span><span>Low Hip:<span class="value">34</span></span></div>',
        standard_size_2_additional_info =  '<span class="header">Measurements:</span><span>Bust:<span class="value">31.8</span></span><span>Waist:<span class="value">24.8</span></span><span>Low Hip:<span class="value">35</span></span></div>',
        standard_size_4_additional_info =  '<span class="header">Measurements:</span><span>Bust:<span class="value">33.8</span></span><span>Waist:<span class="value">26.7</span></span><span>Low Hip:<span class="value">37</span></span></div>',      
        standard_size_6_additional_info =  '<span class="header">Measurements:</span><span>Bust:<span class="value">35.8</span></span><span>Waist:<span class="value">28.7</span></span><span>Low Hip:<span class="value">38.9</span></span></div>',
        standard_size_8_additional_info =  '<span class="header">Measurements:</span><span>Bust:<span class="value">37.7</span></span><span>Waist:<span class="value">30.7</span></span><span>Low Hip:<span class="value">40.9</span></span></div>',
        standard_size_10_additional_info = '<span class="header">Measurements:</span><span>Bust:<span class="value">39.7</span></span><span>Waist:<span class="value">32.6</span></span><span>Low Hip:<span class="value">42.9</span></span></div>',
        standard_size_12_additional_info = '<span class="header">Measurements:</span><span>Bust:<span class="value">41.7</span></span><span>Waist:<span class="value">34.6</span></span><span>Low Hip:<span class="value">44.8</span></span></div>',
        standard_size_14_additional_info = '<span class="header">Measurements:</span><span>Bust:<span class="value">44</span></span><span>Waist:<span class="value">37</span></span><span>Low Hip:<span class="value">47.2</span></span></div>';

    var switchCase = function(thisOption){
        switch(thisOption) {
            case standard_size_0:
                $('#additional_size_info').html(standard_size_0_additional_info);     
            break;
            case standard_size_2:
                $('#additional_size_info').html(standard_size_2_additional_info);      
            break;
            case standard_size_4:
                $('#additional_size_info').html(standard_size_4_additional_info);      
            break;
            case standard_size_6:
                $('#additional_size_info').html(standard_size_6_additional_info);      
            break;
            case standard_size_8:
                $('#additional_size_info').html(standard_size_8_additional_info);      
            break;
            case standard_size_10:
                $('#additional_size_info').html(standard_size_10_additional_info);      
            break;
            case standard_size_12:
                $('#additional_size_info').html(standard_size_12_additional_info);      
            break;
            case standard_size_14:
                $('#additional_size_info').html(standard_size_14_additional_info);      
            break;     
            case standard_size_0_withoutSML:
                $('#additional_size_info').html(standard_size_0_additional_info);      
            break;
            case standard_size_2_withoutSML:
                $('#additional_size_info').html(standard_size_2_additional_info);      
            break;
            case standard_size_4_withoutSML:
                $('#additional_size_info').html(standard_size_4_additional_info);      
            break;
            case standard_size_6_withoutSML:
                $('#additional_size_info').html(standard_size_6_additional_info);      
            break;
            case standard_size_8_withoutSML:
                $('#additional_size_info').html(standard_size_8_additional_info);      
            break;
            case standard_size_10_withoutSML:
                $('#additional_size_info').html(standard_size_10_additional_info);      
            break;
            case standard_size_12_withoutSML:
                $('#additional_size_info').html(standard_size_12_additional_info);      
            break;
            case standard_size_14_withoutSML:
                $('#additional_size_info').html(standard_size_14_additional_info);      
            break;                
            default:
            return;
        }    
    };

    var desktopExperience = function(){
        $(".box").on("click", function(index){
            var thisOption = $(this).text();
            switchCase(thisOption);
        });        
        $(addToCartSelector).before('<div id="additional_size_info"></div>'); 
    }; 
    
    var mobileExperience = function(){
      $(".cart").on('click', function(index){
           var thisOption = $(this).text();
           switchCase(thisOption);
      });    
        $(addToCartSelectorMob).after('<div id="additional_size_info"></div>');     
    };

    if(isMobile){
        //fireGaEvent('Selected Size on Mobile');  
        mobileExperience();        
    } else {
        //fireGaEvent('Selected Size on Desktop');  
        desktopExperience();    
    }

};
sizingIndicator();