overcharging/ increase debit fee no notice

In the beginning of November 2015 my account was debited an excess of R250.00. I did not receive any notice. The call centre agents firstly said this was due to an annual increase of 10 percent, however I wasn't notified of this and secondly the extra amount of 10% is way in excess of 10% .I paid in total an amount of R621.00. I want my money back.