Bad service from PG Glass

I requested quotations through Snupit, and PG Glass contacted me, and gave me a quote. I asked the lady for the nearest branch which is in Gezina Satellite office. I received a Quote for R 1800, and made an appointment for Friday 4 October at 14h00. On the 3rd I phoned the branch just to confirm the appointment. The workshop assistant told me that he has not been informed of any installation on the 4th, as the information has not been given to him. I phoned the number again, those option 1, and the receptionist confirmed that the order has been placed and that I can bring the vehicle in on the 4th. I phoned again on the 4th the morning, and the lady again confirmed that the windscreen has arrived, and that I can bring in my vehicle at 14:00. When I arrived at 14:00 at the Gezina branch, the person told me that the windscreen has not arrived yet. He then phoned somebody, and informed me that the windscreen id at the CBD branch in Pretoria. I then decided to drive to the CBD branch, but I must pay at his office. He then told me to pay R3300, and the original quote was R2800. I refuse, and he then contacted someone and I paid R2800. I have never experiece such bad service in my entire life. I shall not use PG Glass ever again, as they are at the top of the price range, with bad service.