Fnb charges??

I have just checked my account and noticed that FNB has deducted an amount Of R750 for charges that went off due to insufficient funds on No6 items bought on my cheque account?? This is ridiculous and completely unacceptable. Firstly if my account is on R0 no money should go off as I do not have a overdraft facility and secondly I bought something for R35 and you want to charge a person R750 in "overdraft fees" ..... this must be a joke surely?

I look forward to your feedback and rectification of this.