Poor product and service

This company installed an aluminium stacker door at my house on the 20th of December. Soon after they left I noted that the doors was fitted all scew. The door opened on the day but a few days later it sc****d on the tiles soon after one of the locks on the folder door stopped working.... soon after the main lock wouldn’t open rendering the door useless to me for a week in Jan before they started again. Soon after they started again in Jan 2020 they came to fix everything but in the process added a few scratches and a dent in the upper sill. I contacted them again and they sent a new fitter. He replaced the damaged sill and sides but then all the doors were hanging skew again! Rather frustrated I called them back again to come fix it..... which they did, but then there was a 20mm gap between the doors and the frame. They removed the door to fix it once and for all. After they removed the door and took it to the factory they decided to move my door to the back of the Q which will leave my braai room open for 3 weeks!. After a heated discussion we decided that the door will not be refitted and they will refund me. I told Fanie (the owner) that is fine he can collect the parts on site after I get my deposit but they are refusing to refund me this way. I am at my whit's end with these guys!! Be very careful doing business with them! I know everyone makes mistakes , it is how you solve it that makes the difference!