Help filing a claim for being robbed at a restaurant?

Yesterday I was eating at Joe's Crab Shack. I was just sitting there when these two loitering thugs walked in, snatch my phone from my table and ran out the door. I ran out to chase him and he ran into a car and took off. I called the police and when they came to make a report the manager refuses to come out and help me with the situation with the police. The host said to me in exact words "yeah I knew they were suspicious and they followed you around moving from table to table. They did not buy anything and was waiting for a ride" I called head cooperate of joes crab. They refused to help me. Some people told me I could file a small claim for negligence and aware of suspicious people and did not warn the customers and the manager who didn't help talk to police. They even said they had cameras but no tapes. It's just for looks. I wanted to know how to file a claim. They are extremely rude and refuses to help me in anyway. It was a iPhone 5. 600 dollar retail.

Not sure what you want to know. The address of your local courthouse? If you are asking if you can prove the manager had some duty to act to prevent the harm, that is very unlikely.

Help you with what? The restaurant didn't steal your phone. It is a private establishment, but the public is welcome. There's no way the manager could have warned you if he himself didn't know they were going to rob you.
He wasn't in any way obligated to help you talk to the police.
You have no claim, no cause of action.