Very disappointed in diamond projects and interiors

I paid a70% deposit to Tony from diamond projects and interiors to install a roof on a house I'm busy building. Tony from diamond projects and interiors was supposed to start on a agreed date only to start the week after, I paid a big amount to Tony for the job to be completed... After only building half of the roof trusses and installing only half he began with excuses not to complete the work. I've asked him to finish the work or atleast pay me some of the money back so that I can complete the work myself... Still no answer back, and ignores my messages. I would not recommend this company at all, very disappointed