Unauthorised debit from account

I was contacted and asked whether I would like to take out scratch insurance for my vehicle for R99 per month. I declined. A short time later R99 was deducted from my account. As I was not expecting this, it put my account into overdraft. This caused Nedbank to penalise me R120 for a returned debit. Regent contacted me to complain that payment had not been made and when I advised them that I had not agreed to the scratch cover, they apologised for the mistake and said it would be rectified. This month I was debited R198 by Regent, presumably two installments of R99. This has once again thrown me into overdraft with Nedbank. I have to ask whether Nedbank are complicit in these ****s as they are making a fortune out of something that I definitely didn't ask for.