Disappointed with Service

I have a loan with capitec that fell behind and they advised via sms that i would be handed over to Mbd Attorneys. I contacted Capitec as i was not keen on being handed over and i wanted to make arrangements with Capitec and not Mbd! The gentlemen i spoke to advised that the handover to Mbd would be beneficial for me as they will not charge interest and i could pay the account off quicker! I was clearly a fool to believe him because it's been 19 months and I've paid R21500.00 so far but my outstanding balance increased by R8000!!! So what have i been paying? I am so ****ed off because i tried speaking to Mbd but all i get is shouting in my ear and i called Capitec because they told me that no interest would be charged but no one wants to help me. It's so unfair because i put my trust in a bank i gave good ratings to and now I've been disappointed.