BILLED YET NOT REFUNDED AFTER CONTRACT CANCELATION

In January this year I signed up with Planet Fitness Justgym however the gym did not meet my standards so I decided that I would cancel my contract. As per clause 7 of the contract I had cancelled my contract within the \cooling off period"however it seems that Planet Fitness does not seem to abide by their terms & conditions of their contract. It's almost 6 months and I have still not received my refund yet my mums account is still being debited and funds are still being deducted from Planet Fitness. What frustrates me the most is that after cancelling my contract and knowing that Planet Fitness owes me money they still have the nerve to send me nasty sms's and call me trying to intimidate me stating that my account is in arrears"