Poor workmanship and defective product

I had an expanding security gate fitted by Maxidor some months back and was not satisfied with the quality of the work . The agent came back 3 times to correct the problems and only made the problem worse . There is a component of the door that are bent , which I pointed out to the agent - resulting in the door not closing smoothly and sometimes does not lock properly unless you push it very hard . When contacting Maxidor head office all they did was send the same agent back again and then they accepted his report that the door was up to standard , after which they said it meets Maxidors standards - they did not even bother to send out an independant head office representative to check the door despite my requests that they do so. If this door meets Maxidor standards then I must say they have very low standards.