Bridge of agreement

I went in the morning for a quotation at Planet Fitness Just Gym in Vanderbijlpark at SE8, I spoke to Lebo who then called his manager Shaz who then told me there’s a special for Tuesday which will be R299 for the first 2 months then R449 for the rest of the months for 12 months of which I was happy however Lebo gave me a tablet and asked me to sign and I did sign twice then paid for the tag and when home. I then asked where is the contract so I can go through it to my surprise what I was signing was the contract and it says 24 months and the amount is then R449 which was not what was agreed on and I did text Lebo about this misunderstanding and that I want to cancel but he keeps on saying he wants to talk to his manager but so far I’ve not been helped and I have no idea whether my membership is cancelled or not . I even told them I don’t mind losing the R150 tag price but I want the membership cancelled cause they bridged the contract by lying to me and changing what we agreed on.