No notice or warning on the increased cancellation

I've been going back and forth with call centre agents about cancelling my membership with virgin active. I was told that according to NCRA I may pay 30% of the remaining value of the contract. However because I'm a student I was unable to to pay their full R1600 and the agents told me its fine, the amount will decrease as I pay... I carried on paying and now only to find out that I'm back to square 1 owing the same R1600 because Virgin Active increased their cancellation fee to 40% without notice or email. We further don't even receive statements to plan for such inconveniences as some of us are economically pressured and stressed by such corporate actions.