Bank not paying back my money

I wanted to transfer money from my check account to my overdraft account but I made an error when doing that. I wanted to pay R500 and accidentally typed R5000. I went to the Ermelo branch to ask to transfer R4500 back to my check account but they told me they cant help me I have to phone the legal department. I phoned the no they gave me but it just go to a voice mail. I found the number for the legal account on the internet and when I called that number I reached the wrong department. They say they will transfer me to the correct department but every time they transfer me the phone just go dead. Eventually when I got to the correct person, he told me he will transfer my money back but nothing happened. When I called his personal number he gave me he was on leave. I got hold of another person and It was the wrong department again. She gave me the number of the guy who told me he will transfer my money but the number just went to voice mail. IS THERE ANY BODY AT FNB WORKING??