Hi Liza3,
Welcome to Community!
If you cannot change the address on the profile section of yoiur account. if could mean that the address is linked to a debit or credit card added to your account. You may need to update the card detail in your Wallet section on your account. If you still cannot remove the card, I would suggest you send a request through the secure Message Centre on your account or give us a quick call on 0800 358 7911.
Thanks
Martin
