Unhappy customers

I have a complain of the experience me and my family had at Spur Texakhana at the zone Rosebank. We went there for our Christmas lunch and we had the worst treatment. 1. We got the around 15:30 and we only got our orders around 17:15 after we had complained and no one came to apologise or notify us of any delay up until we complained, we had children and pensioners who have chronic diseases and anything could have happened since they were very hungry, spoke to one of their store managers and she offered us free ice creams as compensation, the matter was resolved as the manager apologised. 2. We asked for our bill only to find out that we were over charged, we tried showing them their mistake however they made it seem as if we were the ones who are wrong and probably cant afford our bill, we were humiliated as people in the restaurant started laughing and gossiping about us, even the waiter gave us attitude and caused us drama busy making remarks that we should pay our bill the restaurant would never over charge us or make such a mistake. We stayed at the restaurant till everyone left trying to see what went wrong, my grandmother and children were even sleeping on their tables as they were frustrated and tired, at the end we proved that they over charged us and the bill was rectified however we did not receive any apology from the waiter or even the manager. As we were about to leave the restaurant, the senior manager called us aside and tried to find out our query and promised to send us a formal apology via email for the humiliation and disrespect caused, till today we havent received any apology and we still feel that our rights as consumers were violated. We would appreciate if the restaurant make formal apology as per our discussion.