Arrogant manager at Steers Tygervalley

Today I ordered chips and a milkshake at Steers Tygervalley mall Cape Town. The cashier indicated that the order will take 15 minutes and when I heard the number called was past mine I went to enquire. Then the manager came and gave my chips and went to fetch my already made milkshake in the back fridge. I sipped on it and it was very runny and I wasn't happy with the texture of the milkshake. I took it back and he refused to make it right saying that it was my fault and they already made the order. He just refused to fix it or add ice cream to thicken it... my wife also explained to him and asked him to fix the order but he arrogantly refused. I left my milkshake there and told him he could take it for himself. His arrogant nature really just got me and I will never and I mean never buy anything from Steers Tygervalley as long as he is there.