Cancellation of gym contract

I called to cancel my contract in December. They cancelled my husbands on that call that I made but did not cancel mine. I thought it was cancelled but debit order still went off, I blocked the debit order thinking it was a mistake on their side and had tried calling them numerous times to figure out what happend but my call gets dropped. I have finally now "cancelled" again but now I apparently owe them over R7000 because when I cancelled I also stopped my vitality because I was no longer going to use the gym. I cannot stay on a call long enough to clear this up and find out what happened. I need help