Cannot access mobile service after move

I recently moved and created a new account for my new address. However, I’m unable to find my mobile account because it states that I don’t have any Xfinity service. I spoke to someone over the phone, and they informed me that I don’t have service through them. When I called, it showed AT&T service. They’re unable to resolve the issue and suggest starting a new service and getting a new number, which I’d rather not do. Can anyone help me figure out how to resolve this issue?