No communication

Good Day, I have paid up my credit card and done so in excess. I have requested for a paid up letter as well as a refund for the monies in excess close to a month ago and I have not received any other feedback other than "supply us with your banking details" which I did on the day the request was made on the secure mimecast portal that ABSA redirected all communications to.

I have further laid a complaint on ABSA's official complaints channel and that has brought no resolution as there has been no communication or acknowledgement.

Can someone please assist me in a more timely manner?