My contractor has left the job and is unwilling to complete the job agreed upon. What can I do?

Purchased house. It was gutted and rebuilt. Contractor has walked off the job multiple times, each time we had delays and had trouble communicating with him since he refuses to respond. This time, he is not returning and hasn't responded to any communication. He has taken about 90% of the payment but has left over 25% of the job unfinished. We do have a written contract signed by both parties about the work to be done in detail and a scheduled date of completion, which is overdue by 6 months. Furthermore, I suspect his employees of theft as there are many tools of ours missing. He has always made claims of having knowledge of completing the job to regulation and that is licensed to do so, but this doesn't seem to be the case. He has continuously wasted and improperly installed materials, which he has refused and is neglectful to correct after obvious errors were described and shown. He was a referral from the architect, who guaranteed his work, but is also refusing communication.