im very very mad at the service I got

I opened a account in 2012 at bushbuckridge for R4000 building material and had to pay R6000 in total for 12months they said in included insurance hence I had to pay insurance should anything happen to my job then the bill would be covered..3years later im trying to apply for financial assistance they telling me they can't help because I have an account thats in arrears? Hows that possible? I paid my account fully every month no missed payments till I lost my job but I only had R1200 to pay and according to the insurance theory they gave me it should be paid off.i dont know if the woman that assisted me was *********** but then again how hire *********** stuff to handle financial issues?I called today they telling me I owe R5700 due to interests what intrests?.im not gonna pay such a ridiculous amount for being miss fed information why is it my problem why do I have to suffer for it?all you guys can say is sorry but i still need to pay.No!!I demand that my name is cleared from all this.i did as I was told.deal with your stuff hire competent stuff.the worst service ever.i wouldn't recommend anyone to get assistance from the company