Bad service

I went to buy fish and chips special for R29 I opened it to check whilst I was still at the store. I told the cashier that this was very small. She immediately called the manager who his stood at the back of the kitchen and said its a normal fish what can she do. Her attitude really sucked. A day before i bought the same meal at Eastgate it was so big and well presented. I even told her that. All she said it could have been long but the scale is the same. How possible is that. And this was not the first time I compliant to the same manager about the quantity id their food. I will never go back there. She obviously needs training on customer service and will tell all my friends and family about this pathetic service.