I don't think they can change the address.
However there may now be 2 different ones and it is signing you into the wrong one
you should be able to click on the little profile box on the top right and select sign out and then sign into the other account. or it may show both accounts and you can just click on the correct one.
If you are using a device other than a computer it may be a little bit different as to how you do it. But i am happy to give you my phone number and remote into your computer or talk you through a device like a phone to get it straight.