Bad Service at PG Glass Sandton

I booked for a windscreen fitment on 29 Sept and I paid online. I went to PG glass Sandton branch and they booked me for 11am on 30 Sept. After the glass was fitted, a sales representative called Thabo said I could not collect the car unless I had a proof of payment. Question: On what grounds had they fitted the glass in the first place as they had checked on the system? I called my bank and they said they could not reverse the payment. They gave me an authorisation code to give to PG Glass to complete the payment. Thabo refused to assist. I paid for the fitment using my card as a new cash payment. I went to your offices at BedfordView and they gavce me a refund form and said they would call me. I have not had any call. I want my refund. Work Order Number: *** Cash Receipt: ***