cancelled membership that is debiting ,

In august I went to planet fitness 98 MAUDE STREET,SANDOWN in August to sign up for a membership after I was told by Vusi that I will get a 50% discount since I'm a momentum medical aid member, was happy because that would fit my budget , then the next thing I get a debit order mandate that shows the full amount , called and cancelled that instant and confirmed the membership is cancelled because I knew I wouldn't afford R849.00 to my surprise on the 30/09/2025 I was debit and want my money back , called Vusi and let him know that I need the refund because that money had other commitments then he told me I'm giving him drama. Please assist with my refund planet fitness , I can't reverse the debit order from my banking app or my bank.