This is my correct account, but the problem

This is my correct account, but the problem is with the phone number. It tells me the phone number is incorrect, and there is another phone number connected in your account, and I try to delete this phone number, but I cannot, because I do not know the phone number, and my phone number is 5024034439. When I try to enter the phone number, I am not allowed It says there is another connected number in your account and you should delete it