Slipping and Sliding like the doors they fit

Engaged swiftslide's owner to arrange the fitting of glass-front cupboards at my house. I was professional and so was he. The date of the installation I was not on site but my helper was. I returned home about 3 days after the job was complete and my helper pointed out that the one door had a crack. I engaged the owner, who first promised to send a team to check, after 5 such empty promises from him, my tone changed and i expressed my deep distress. He responded with 'well the job was perfect when we left' only for me to discover that he was not even on site on the day of the installation. He's made empty promises to come fix, and to date - almost two months after the job, the door remains cracked. I paid on time, engaged professionally and was a model client - so it is sad that now that he is fully paid, he feels he can just refuse to fix the door and delivery proper after-sales service