Problems with masonry contractor. He did not follow the contract, and stole items. I cut his bill in half. What should I do?

The masonry contractor did not follow the contract. The contract said to remove all brick steps and install Belgium blocks with blue stone on top. Instead he kept the brick steps and only created a Belgium block face in front of the steps. He did put blue stone on top. The second problem includes stealing a lawn mower and vacuum cleaner when no one was in the house. The work is at a rental property, and the tenants had just moved out. No one was around and they helped themselves to a lawn mower that was in the shed, and a vacuum cleaner in the house. They probably needed the electric outlet that was in the house to do the work. They must have climbed in through a first floor window, since I noticed that the door to the steps were unlocked from the inside. While inside the house they stole