NEED REFUND ON FEES

I need an refund on 3 transactions. Bank charge ridiculous amount of R90.00 per transaction for overdrawn account-I always have a good account and never go overdrawn.There was an transaction that was accidentally taken and in this time the other transactions went off whitch was behind my control .I need my refund as I have a good standing relationship with FNB and this will not happen again. R90.00x3=R270.00