Unauthorized DebiCheck

I have lost an amount of R2200 through Capitec via a DebiCheck When I tried reversing the lower amount it says it cannot be reversed and when I go into a Capitec Branch I was told both amounts cannot be reversed because they are debited through a DebiCheck and Apparently I have approved that DebiCheck and I did not I was told that I need to contact the company responsible for the debit and ask them to reverse the money. Now my question is How does one negotiate with a bunch of *******? And secondly most of these companies are non contactable. Is this the new era of losing our hard earned money?