No service from FNB

The whole FNB correspondence is a mess. My mom has requested that her credit card be cancelled. We have done it via message function on the FNB app. We were told that the request would've been passed on to the credit card division. To date we have not received any further correspondence. We have also sent a mail to my mom's private banker and we also haven't received any correspondence. We just want to close her credit card account. It is as if FNB don't want to help clients, that is why they use the FNB app for correspondence. They don't want you to email them or have proper contact with them. Just close my mother's credit card as requested