No customer service

I have been trying to update my card details since May without success, I'm on your website now and able to go as far as verifying the transaction on my banking app however card details do not update on your platform. 3 of your agents previously tried with me on the phone and they all failed to have the banking details updated and was promised a call back on the 30th of May for further assistance and that has never happened to date. Missed payments due to incompetence on your end continues to affect my credit record negatively.