Unbelievable threats by FNB!!

I was at FNB Meyersdal on Thursday exchanging money the teller over paid me by R400, When I got back to the office I noticed it but was unable to get back before 4 when they closed, They did phone me that afternoon and I did tell the teller and manager I can't make it but will bring it Friday, I was unable to get to them on Friday as I finished to late but it did not stop them from phoning me 3 times and I said if I can I will come past saterday, I forgot my phone at home where the teller phoned me again 3 time and my wife said I forgot my phone, The teller then threatened to freeze a business account until I paid the R400 she over paid me!! I did not know a teller can freeze accounts!! I can't believe this is how FNB treats there business clients!! I wish I could go lower then 1 star