How can I recover the default resource group in my free IBM Cloud account?

Question

I have recently enrolled in the Data Science IBM Course and many exercises make use of IBM Watson Studio. I have acquired access to it on my free account, however, when I tried to use it 2 days later, the default resource group in my account disappeared. Does someone know how to recover the default resource group? Whenever I try to acquire other services, there's an error message informing that I do not have resource groups available, which is strange, since a couple of days, it was fuctioning perfectly.