bad assistance

I have the worse issues with the Lewis group since I have a furniture account with them. I have been paying them more than the instalment for over 2 years and but when I asked for assistance or when I get phone calls from the branch they are abrupt and rude to me when I asked them that I would like to know what my settlement amount is, as I would like to settle the account before the time they gave me a ridiculously high amount of R8000. When I bought the furniture it cost +- R15000 with their interest. After 2 years of not missing instalments and paying more than I should on an instalment they saying I only paid in R7000, next year is the last year in which the account is to be finished so I wanted to pay it up before the time. That doesn't seem right to me then they still give me bad service as well. I am very unhappy as this has been a constant problem I have with lewis stores and their employees.