Poor after sales service

We had extensive aluminium stack doors, windows, normal doors installed by AGA in 2010. We requested a number of times for these doors to be serviced in 2011, 2012, 2013. The services were initially prompt, but thereafter slowed down to ultimately in 2015. In 2015 one of our stack doors would not close as a dead bolt had broken. We contacted AGA and were then referred to Panamera (Denzel) as their appointed service agents. Panamera arrived, replaced a dead bolt then proceeded to spray lubricant on all hinges leaving drips or oil on door frames. After attempting to charge an exorbitant fee of R3000 for this minor repair, we settled on R1500. Needless to say the same door supposedly repaired is in a worse condition, rivots came apart and we now cannot close the door. We contacted AGA and after 6 weeks of request, Frikkie eventually came out to inspect. He informed my son that there was nothing wrong with the door and left. THE DOOR STILL DOES NOT CLOSE!!