Poor Service

I purchased a groupon Voucher for Autotec VTS in December to do the Smash and Grab tint on my new car. When i made the booking, i informed the person i spoke to what car i had. The person took the booking and did not tell me anything else. On the day of the booking, i was made to wait for 40min and then a person called Phati of Party informed me that my car (which is a medium car) was a large car and that i would need to pay an additional R350. While i was sitting and waiting for service, other customer had come into the store and were also complaining about the bad service. I then asked another customer who was a gentleman in the store if my car would be considered a large vehicle and he said \You know what just leave?". I am not sure if it is because i was a young female that they thought i did not know what i was taking about and the company was very quick to redeem the groupon voucher without providing any service. They are a total ripoff. """