two factor authentication phone number no longer in use

Hi, my elderly Auntie has an iPad, and she got a new phone and phone number a while ago, but didn’t update her Apple ID two factor authentication, so now it is trying to send a code to her old phone number. When we click that she dont have this number anymore it just gets stuck in a loop of trying to send a code to her old phone number. We went to the iforgot page to try and fix it, turns out she has also changed the bank card that was registered to her apple account so we can’t reset it that way. We went through all the steps and got a message saying we would have to wait about a month, and then she would get a call or text on her new number on August 31 but this never happened. Any idea what to do next? Her iPad is stuck trying to send her old number a code so she can’t log in to anything with her Apple ID. Any help would be much appreciated.

thanks