Appalling customer treatment

I had bought a Brazilian blow wave voucher on groupon, I called immediately to book as I wanted it done before I left for my vacation and made it clear to the person on the line that I wanted an appointment asap and I wasn't available after the 15th of December 2015. She told me they had an availability on Saturday at 1:30pm and said I was booked. I arrived there to a receptionist who said I wasn't on that date but the next and I tried to explain I had requested it asap but the receptionist basically told me I was lying and that I was lucky I got an appointment on a Saturday because they're usually busy. I understand an error could be made between both parties but I did not appreciate the hostile conversation and accusation that I was lying. If you are looking to go to the salon to get your hair done and make you feel good I DO NOT suggest classic hair and beauty salon in the radisson in sandton.