Poor Service from Manager

Earlier today we went to go celebrate my brother in-law 40th birthday but we got poor service in Strand Beachroad. The waiter made long to take our order. I don't wanna sound ****** but 2 groups came after us & the waiter who served us made quick with their orders and was friendly with them. We requested the manager and he also gave us attitude. While we tried to explain to the manager what happened he walked away. When the manager returned he told us he put pressure on the kitchen staff to make quick with our food. When we tried to explain to him he walked away again and we told the manager its rude to walk away from the customer. The manager's reply to us was that we won't understand, he try best to keep everyone happy. We just wanted fair service and respect. He told us to keep calm and keep quiet! How dare he?