Charged for additional pizza I never ordered

I was at pizza hut mall of South and I was asked to use the self service machine to order to pizzas. One of the ladies assisted after the Manager, Vuyo did not know how to change the selection to a medium pizza. The system added an additional pizza, which the lady at pizza hut deleted from my order. The system then charged me for 3 pizzas and Vuyo refused to assist and was rude. He did not want to refund me the charge for the additional pizza which I did not order. Never order food from Pizza hut. All I want is my money back. If I go to any other store they will immediately do a refund either to my credit card or pay via cash. Pizza hut is robbing customers. While I was at the store chatting to the Manger of the store another customer had the same issue and had to bring his bank statement in to prove his bank account was charged. This is unacceptable. Why must the customer run around when clearly your system doesn't work. You are *****ing people's money.