Terrible after sales care

Weeks after fitting two patio doors I'm still awaiting a new barrel/lock which they claim to have ordered but hadn't. I constantly chase but nobody ever calls back in regard to this. I'm booked in to have the doors adjusted and a large scratch repaired on 12-08-16 but they now deny that this appointment was ever arranged. Customer service is appalling and rude, they are not the least bothered about making sure defects are amended and have no conscious about ignoring you. The doors were fitted on 23-06-16 and I still haven't been issued with a receipt of full payment (having asked numerous times). I advise strongly to keep well clear of Smith's Glass Limited as they are unprofessional, untrained and have no idea of customer service whatsoever. I now have no alternative but to start legal proceedings which upsets me greatly as I'm trying to cope with setting up a new home with my disabled mother and managing the care needs of my father who has severe vascular dementia. But this company doesn't care about the level of service given to the general public as long as they get your money. So basically their 10 year guarantee is worthless!