Bad Service & Incorrect Billing

We've had a long standing account with Lewis Store at Boitekong Mall. We paid two installment for two months at their Rustenburg: president Thabo Mbeki drive branch. Our balance was not updated after the two payments. I reached out to their call Centre and I logged a complain, they've never gave me any kind of feedback. I followed up yesterday and they haven't resolved my complaint. I asked area manager and store manager to resolve this and come back with resolution. I asked them to include me in their email communication so that I can be kept in the loop as I already haven't heard anything from them, they've not been proactive at all. I want them to attend to this, I need this to be resolved ASAP! It's also affecting my credit, these payments need to be updated and a new statement needs to be drawn up!