Wok In Wok Out

Today, I went to the buffet with my wife, my sister and a good friend. We were directed to a four-person table. We were having a great time and ate lots of food before receiving the bill. This is the part that vexes me. When I pay the balance that is owed, the manager demands a TIP, otherwise I can't leave. Everyone else has left, but me. He even looks in my wallet for a ten dollars to take out. Because this a buffet and I ultimately serve myself, I do not believe I should leave a tip. For what getting a drink and cleaning a table which is required anyway. He even has the decency to call my wife a offensive name. THE RESTAURANT IS TRASH AND SHOULD BE SHUT DOWN FOR UNFAIR PRACTICES AND FORCING TIPS ON CUSTOMERS, THAT IS ULTIMATELY MY DECISION WHETHER OR NOT THE SERVICE WAS GOOD. IT IS NOT OUR FAULT THE EMPLOYEES CHOOSE TO WORK FOR LESS.