Trying to cancel contract

I would like to find out how Planet Fitness finds this fair and reasonable?

I want to cancel my gym membership and Planet Fitness wants to charge me a 30% cancellation penalty on the remaining 3 months (April, May, June) of the contract and they will allow me 72 hours do this.

I then asked what would happen if I cancel the contract on 30 March. I was told my account would still be debited for April and the cancellation fee will be calculated on the remaining 2 months (May, June) BUT I will not be allowed to use the gym facilities for the month of April although I would have paid for it.

How is this fair and reasonable? You want to take a month's membership fee AS WELL AS your 30% cancellation fee to allow me to cancel a contract????

That amounts to a 80% cancellation fee!!! (R549 x 2 = R1098 x 30% = R329.40 PLUS R549 = R878.40 of R1098 = 80%)