Contractor ran away with deposit and left job unfinished

Bell's maintenance quoted to do a couple of jobs around our house. They asked for a 70% deposit. During the work we asked him to ensure the quality of the work was up to standard, as we were worried that they were not putting the care into their work. After 70% of the work was done they disappeared without saying a word. Graham the owner has ignored my calls ever since. His ***ardice has left us completely in the lurch.