Waiter Drinks leftover Juice in bottle!!!

The reason why I am leaving out the waiter's name is that he has done wrong but it is also not his fault as management probably told him to do it that way. My self , mom and grandmother went to the new Fournos Bakery at Mall Of The South in Alberton on Saturday. We sat down and ordered 3 Fruit Juices and 3 cream doughnuts. I looked at the waiter as he was busy poring the drinks from an Sir Juice bottle the 500 ml one in to an empty glass he filled the glass and there was still left in the bottle. I thought he would then bring it with as an customer I am after all paying for it he instead goes around the corner and drinks the rest of the juice. I was very shocked at what I saw. I also have an small problem on the pricing of the juice that same Sir Juice you can buy at PNP, Checkers, Spar for around R15,00 depends on what flavour. It will never be more than that. I bought that same Juice for R25,00 at Fournos and I really feel that is an ******* to the customers. I really think if someone buys juice the customer needs to open it or the waiter can do it when he is at the customer.