Bad service

We are a big family and we had a reservation for 2pm on the 25th of December. We phoned to lodge a complaint on the 26th because we were unhappy about: 1. The waiter were upset about the fact that we popped crackers that was placed but we were taken to a wrong table. 2. When we made the booking we asked if my mother in law can bring her own chair to sit comfortable and it was confirmed that it would not be a problem, however when we got to our table we were not catered for. 3. We had to ask for our starters after we were told to dish up from the buvet. 4. The beef roast was so dry it looked liked dried out liver. 5 . The gammon did not look like gammon it looked liked cold meat. 6 .The food that was prepared was cold and it looked like they were not ready to serve. 7. One of the children at our table went to dish up prawns again because its a buvet they said eat as much as you want but when he wanted to dish up more prawns the child was sent away and told to wait because he dished up several times 8. When we lodged the complaint on the 26th with the manager Adele she told me that the waiter was dissapointed in his tip so i told her its because we were not happy with the service we received. She also told me to keep quiet and listen to her as she is the one who is upset because she received a call about such complaint. Adele was informed that we will not be eating at their restaurant again because of their pathetic service and because of the fact that they do not know how to treat customers.