Paid up letter and ITC

After I complained about Cell C few days ago a consultant called and few minutes he confirmed that Cell C did received my proof of payment and he then emailed me the paid up letter. After two years of battling with Cell C. I paid for a debt I didn't know about as they failed to resolve my complaint. It is fair that they don't apologize for listing me on ITC. The stress and the pain they caused. The insult I received from the HHP attorneys. I need Cell C to explain to me why it took them two years to respond back to me.