Bad service from Lewis

A few months ago i broke my leg and couldn't get to the Store to pay my monthly installment. My account was then 1 month behind. My installment is R770 per month. Last month i called the store and asked how much i need to pay to get my account up to date. I was informed that my account was behind with R1210. I was also informed that i needed to pay R1910 which includes my installment for the month to get the account up to date. R1210 minus the 1 installment that i missed is R440. I accepted this as interest charged and paid the R1910 to get the account up to date. I was called and informed the account is still behind with R820! This means i am charged R2030 for 1 missed premium!!!!!!! ****** i tell you. The lady who called me promised to call back on Monday - that was 2 weeks ago. Still nothing. Send emails...still no response.