Deposit repayment

We booked a vacation at Langebaan with Langebaan holiday homes, overall, the service was fine, but when they needed to repay our deposit, they decided to take R950 for towels that were never even in the room in the first place. They say that there were supposed to be 8 towels, but we only had 4 towels for the whole week for 6 people. There was no checklist or anything like that to show that the towels are supposed to be there.