Irish Harp serving bite size meals & charging full

My daughter, 2 grandchildren and I went for Lunch at the Irish Harp Restaurant at 40 Loch Street, Meyerton. My daughter, eldest grandchild and I ordered stuffed spuds on the menu - prised at R52 each. I have ordered this of the menu before and could never finish it because of the generous portion. Today however the size of the 'stuffed spuds' were half the size of my fist and it was not at all stuffed. It looked as if one potato was cut into three portions divided into the three plates with with sauce over it and a large salad with raw peppers which we also did not ask for on the side. When the plates was placed on the table I immediately asked the waitress Elizabeth to call the manager as it was really quite ridiculous. She responded by saying the manager is only going to charge us half prise we still asked to see the manager and she told us that she is currently very busy with another table, so my daughter took pictures of the plates and we started eating. After eating the tiny meal we asked for the bill and and the manager came to me and told me that we will get 10% off. I told him that it is ridiculous but he did not care. Irish Harp you will not be seeing me again!!