Cannot talk to call centre-PROBLEM money paid into closed account

I closed all FNB accounts due to bad service. A customer paid money into one business account after it closed. Have emailed and filled in a request on FNB online. Received one response, was told to call ********** select option 1 or ********** (24/7 line) . TRIED BOTH REPEATEDLY - impossible to talk to a human. Keep getting asked to fill in ID or account number. Tried both - it tells me invalid entry - yes I know -I am not an FNB client anymore. So how on earth can I talk to somebody - IF FNB WONT LET ME TALK TO THEM!!!!!