Treated unfairly

I went to Virgin Active Menlyn on the 4th of September to sign my gym contract and pay my fees. This was done successfully and I was told about the Adidas promotion they were running until the end of November where you had to visit the gym 24 times to receive your activation fee back in a voucher from Adidas. Using the website functionality provided by Virgin Active, [URL Removed] to monitor my visits so that I could track how many times I would need to go. I reached 24 visits before the end of November and could not attend gym any further, which was fine because I already achieved the requirements for the voucher. To my surprise I never received the voucher so I tried phoning the Virgin Active head office to ask why. Apparently they only processed my contract on the 6th of September even though the website told me that I had visited the gym only 23 time because of that, why did they count it? After making me feel like I am trying to **** the amount of times I visited and like I am trying to cheat to receive the voucher by the call center. Really disgusted in the way I was treated by Virgin. I would cancel my contract and rather move to Planet Fitness if I could.