During kitchen renovations, contractor brought a guy to design and install the kitchen cabinets. He brought the base cabinets and installed them and is asking for the rest of the money before finishing. He already got paid for half the agreed upon fees before starting. His cabinets were not what we had agreed on and wasted a lot of cabinet space and most his measurements were wrong. We thought we had come to an understanding and compromise but now he says he has to get paid in full before agreeing to finish the job. What are my rights?