Why can Capitec not assist me!!!!

I requested a report online via Facebook which was on a special of R17,95. I went ahead and the next thing a transaction of R275 was debited from my account. As there was insufficient funds in my account, the amount didn't go through. I then went into Capitec Bank yesterday and stopped my card and was provided with a new card for R70,00. And this morning, there the amount went off my account. I went into the branch again to try and stop it and was told I need to provide proof. My problem is, I did not authorize the payment. How could it go through and I'm unable to dispute it because I cannot find the original Facebook offer. So I have lost the little I had. The worst is ot shows as recurring. How do I stop this!!! At the bank they tell me they cannot help me because it's a ****. Our banks should be able to assist us. If I haven't authorized it, no one should be able to take one cent from my account. I'm contemplating closing my account because of this!!!