Overcharging regularly

We visited the Palms Restaurant on Saturday 30 April 2022. Prior to our visit we booked a table and paid a deposit for 3 platters. Roxy was our "events coordinator". At the end of the evening they charged us for 4 platters and did not subtract the deposit. We did not notice this at first and paid the full amount. For a week now we have been trying to get a refund of almost R900 but with no success. We have all the evidence in the form of slips. E-mailed them, phoned them but they just ignore our attempts. Please check your bill before paying. This is the 3rd time this has happened to us. We are never going back