Bad Attitude And my billing

Good day, I have receive an statement on the 8th of September 2015 stating that my closing balance is R 4 541.76.On the 17th of September 2015 I have made an payment of R 4 541.76. The total amount was paid. Then The end of September I have received an statement that the closing balance is R 100 and something. I paid that as well.So that means my account is fully paid and there is nothing outstanding So from October 2015 I have not receive any statement stating that there is any payments that need to be made.So that means the account is fully paid.when I placed several orders I have received an ridiculous statement for 2 Months now. And every freaking time the assistant lady is rude and has an bad attitude.Now the information that is given to me is that there was not an settlement amount requested and that is way my payment is R 871.56. = R404.91 (Bedding that was paid in September and paid in full) The rest of the order adds up to R 475.16. That amount i will pay the rest I will not pay because the account was fully paid last year. Please check your system and correct your system before the end of this month. How can you expect an customer to pay for something that is fully paid?