Edgars complaints

This is now the 3rd time that I complain about Edgars since RCS took over. Firstly I cannot understand how they calculate the Amount owing, the closing balance and opening balance. My owing amount keeps escalating in spite of payments. The issue of interest is such a thorn. I once complained about the 6months plan and interest. They corrected it at one stage and credited me. However they charge ME for principal adjustment as if I requested an adjustment. They also put me on a 30 month budget plan which I don't understand. A few months later they charge me interest again. I complain and they credit me. They are still charging me a 17.50% interest, why I do not know. For the past 3 months they put me back on a 20 months revolving plan and 6 months interest again. I have not bought anything from Edgars in a long time, almost 2 years. I am only paying for insurances. In spite of that, my balance owing keeps on getting high even when I am paying. I feel so TRAPPED and completely disgusted with RCS. Dealing with Edgars is like a full time job. Where can I complain? Is there an ombudsman that I can contact and deal with the mess at Edgars?