Virgin active increases my fees by R140 without my consent!

I signed a contract last year for 24 months on a fixed fee, the only fee increase that was communicated to me was and inflation increase of R20. The without my consent or even notifying me Virgin bumped up by debit order with R140. All the staff except one was rude towards me and none of them could help me. I went to get my contract at the club and read trough it, in the contract is states my fees will stay the same for a 24 month period except for a inflation increase of R20. I am a student and R140 per month extra is a lot of money for a student. Two of my friends have exactly the same contract as me signed at the same time and their fees did not go up and no consultant I have spoke to yet can help me or explain this to me, they all just say thats the way it is...will never have a contract at virgin after this one is concluded again.