Poor after sales service and refunding issues

The quotation phase went okay, I was very excited to see the product and all seemed okay. Never did they tell me that they deliberately did not install a certain section of the quoted gutters. This is a section only visible when you are on the roof, since it is part of an overhang over a built-up room. They just kept quiet, not telling me about it in order to devise a new plan for that section. Maybe hoping I wouldn't realise.....this worked for a while. I only realised it when the first rains came and had problems with that, since they removed the old gutters, didn't place the new one as contracted and also didn't check the roof sealing. Just goes to show that you cannot take them on their word, I guess I should have looked more carefully when the job was done, maybe I should then have checked all brackets, *****s, spaces between downpipes and the wall, etc as well. Problem now is getting the money back for the part they did not do. Last response was in May where they promised to refund me but to date nothing has happened. Definitely not a supplier I would recommend!