FNB Close account.

Need to close my dad's account to settle his estate. What a mission. I did report it to the branch, completed all the forms, and received a rev code. After one week I phoned the service desk to get the status. At first, they say I did not complete all the forms but when I proved to them I did, they acknowledged they have it. They promised to process the request. After the second week, I phoned in again with the same story, they will process it. The third week the same story, When I asked where can I escalate the request they put the phone down.

Who can I phone to resolve this?