Call the Surety bond company

Surety bond is insurance for construction projects. Every legit contractor would have it. It guarantees that if the contractor does not finish the work, the surety company would step in and finish the work. Most state requires licensed contractors to have surety bond just for the situation you are facing now.

i don't know kind of project you have. Sometimes surety bond is called "construction bond". Look in your paperwork of contacts for such company. Contact them and you should be able to resolve this.

http://en.wikipedia.org/wiki/Performance_bond