Cheats people by debiting a/c twice & not refundin

I took Planet fitness membership through discovery vitality. I cancelled my contract with them hence I had to cancel my contract with Planet fitness. I took a new contract and paid for a year in advance. They are still debiting me for old contract for the highest amount of 500 Zar per month. I have told them multiple times to refund me the money but everyone seems to make an excuse for the same. I have asked Planet fitness Rivonia Manager multiple times and also went to head office but no one seems to care. They have to give me around 2000 rands.