Gardner refusing now to pay me the £800 it has cost me to rectify his.

How I can get this back I’ve done everything Rated People have advised me to do.but still no joy.i won’t this company taken of the website advertising his work.its disgusting that he is carrying on,yet not fulfilling the job I paid him for,£2,400,and then another £800 to have put right.Rated People have been in touch with both parties over this and said Mr.Stillwell has agreed on everything I’ve said but still not paid me ? How can this be allowed or fair ? I used Rated people as I thought it would be genuine trades people,but never again would I use this site for more tradesmen.