I’m a landscape designer and pm. The sub I hired to install a job did a Terri le unacceptable job. I didn’t have faith he could do the job so I fired him. Our contract was just a scope of work with itemized prices but no termination language. I paid him for half the job up front and he completed about a quarter of it. I want to pay him for what he did and get the rest back. Do I have legal grounds to do so?