Staff Robbing/ Really Accident

I came to Adega Midrand tonight. We come here quite often. We got served by a waiter that always tries to up our bill every time we come here. My daughter took a magnum from their ice cream kiosk. When the bill came it stated R40 for a magnum milkshake which should not even have been the case cause it was an ice cream. And even if so the special said the milkshake was r29 with a main meal. We asked the waiter is her absolutely sure it is R40 cause it is soo expensive for an ice cream and he kept insisting it was right. And we tip him quite a decent tip. We called another waitress and asked her about the price and she said it was R30. I asked if she was sure and she said yes and said this guy charged us R40. So she said let her clarify. She went to the front and suddenly the waiter came back and gave us the R10 and kept apologising which I do not believe was genuine. He was clearly trying to make a quick buck has he has been working here a while and would know the price. Ruining Adega reputation