Verification code for debit card in Apple Pay, phone number is wrong and won’t change

I’m trying to set up my debit card in Apple Pay, but no matter what I try, the phone number for sending the verification code via text message won’t change.

Most bizarrely, it’s not even a number attached to either my bank info or any Apple ID settings or contact information, so I don’t know where it came from and why it won’t change.

I saw that other people have had this same issue before, but the suggestions and replies were not helpful at all :( They all said the same thing about getting Apple ID verification codes in the settings, but that’s not what I’m looking for.

I have already double and triple checked absolutely everything: bank details, Apple ID, wallet info, contact info, etc. That number wasn’t listed in any of them, and it’s definitely not the number I used to sign up my card with at the bank. I’m considering calling my bank and asking if that number was somehow put on file by mistake, since it’s definitely not mine, and they could be contacting a stranger for all I know!

I’m frankly really frustrated by the lack of available information, and I just want a genuine answer as to what’s possibly going on, and not just a reply linking how to verify an Apple ID.

thanks.