Poor customer service

I'm not happy with FNB customer service. I have been their loyal client for years but I feel when it it is time for them to assist me they don't. On the 23 December 2020 I deposited money to the wrong account. The recipient had problems with fnb and their account is on excess. They can't withdraw the money and give it back to me. I completed the reversal form and was told that I will get response after 10 days. I don't understand why because the money is in the recipient account . They say the reversal is not guaranteed. I need the money to be reversed urgently. I have been sending e mails with no response. I have used the we chat service but I'm not getting the assistance I hoped for. I feel it is not fair for a loyal customer like me to be treated like that