Bank charges for YOUR mistake

It has become so hard to deal with FNB - I have multiple products with FNB and I have to call 3000 different numbers for a service. I have a life cover - I changed my banking details on 19 Nov by telephone - they debited the wrong account and charged me exhorbitant return debit order fees. When I call in, the advisor says they cannot see the day I called in - and the dept I spoke to must take responsibility but they cannot help if I dont have the exact time and number I called from. I called form a work soft phone - I dont know what number appears when I call. But now it is my problem. And the advisors have attitude as if you are a nuisance. The advisor tells me the debit order is on the right account but records clearly show it went off the wrong account. Regardless of when i called or who I spoke to - the wrong account was debited and I want it rectified and I want my money back from the exploitation of the penalty fees that I must pay because of your mistake.