Incorrect billing, wrong payments and wrong statement

I have a problem with my account at Ok Furniture roodepoort, I bought my bed in July then i paid the deposit, since then i have been paying my account but now i need to settle the account, the statement from OK Furniture roodepoort shows that I bought the bed in September and only shows two monthly payments while all in all its four payments done to the account. Can u please help me that they rectify this mess because I need to settle this account, and I can't settle before the two payments included in my account, I was wondering why this account is not moving when I pay, mess is created on this account