Account Balance

I have been paying my woolworths visa account with Mooney Ford Attorneys for the last 5 years now. I enquired about my balance on 13/10/2015. I received an e-mail on the 14/10/2015 stating that my balance was R2520.00. I continued paying my account of R400 per month to Mooney Ford. I asked for another statement on the 07/03/2016 to settle my account, and i received a balance statement of R2273.34. I have received a statement dating back from 2010. The initial debt taken on R22000 and i have paid in excess of R31000 and still have a balance of R2273 to pay. I think that i am being bul**** by this company, as i havent missed a payment, and i have always kept to my payment promises. I have not paid this month as i will await an outcome from them.