Planet fitness gave me wrong information

I joined planet fitness on the 4th of November 2019 they told me isR149 if I join using sanlam reality and they are giving me nov and Dec for free,now the tell me is not R149 is R750 and I have to pay R925 For activation fee. I call the call center and asked them to cancel my membership, they refused to cancel it and told me that I have to pay R5000 within 24 hours before cancelling.