Fish aways false advertising on meals online

We ordered a Good Life Meal for 2 which said 4 pieces of hake - medium rice and medium chips and two small coleslaw and small calamari strips priced at R177-90. When the delivery arrived we only had two pieces of fish and immediately phoned the branch and was told no just two because it is big pieces. Nowhere on the ad does it say anything about substituting for two bigger. We had two guests that did not get their fish because we only got 2. I phoned the manager about twenty times and had no joy. Not even from the query line. So overall I got really bad service and was not happy. This to me is false advertising and such terms and conditions should be shown if that's what they do. Staff should also be told to make this change known to customers. Fish aways has lost a good frequent customer now. This matter should be addressed