CANCELLATION UNSUCCESSFUL

HI, I've cancelled my gym contract on the 1 of July 2015 giving 2 months notice. After several attempts my gym contract is still not cancelled as the debit order still goes off my account. I've put a stop order on the debit order, but Planet Fitness change the amount so the payment can go off. PLEASE SORT THIS OUT, AS I'VE REQUESTED 3 TIMES ALL READY. I think it is very unprofessional and to change the amount so the stop order does not pick it up, is *********