Unauthorized debit order and empty promises!

I went to Planet fitness Benoni for the week trial that I got online and I just wanted to try the club out before I could sign up. But I was told o need to sign up to redeem the voucher and later cancel of I still want to, I told the manager that I’m skeptical about this process because I want to avoid the admin of having the debit order go off my account and I have to ask for a refund, that process is tedious and I don’t want to put myself through that and he gave me his word to say it won’t get to that point. Guess what??? It did, I sent the lady who helped me a message that I would like to cancel and she gave me an email but it wasn’t canceled and the debit order was scheduled to go Through. My account is now on a negative balance and I’m incurring charges, I asked they reverse their request but no one seems to be paying attention now I’m being told that they don’t know what happened cause they sent the cancellation, how am I supposed to know when they don’t follow up? I’m highly disappointed of what I thought it’s the best club that I would look into joining next year but this makes me question their integrity.