Poor communication with customer

Good day

I would like to review cell c .their service is really poor and disappointing .I had a cell phone contract with them which ended up in arrears, I am not disputing that but I have paid da whole amount of arrears 4 months ago .I have been sending tons of emails asking them to update this information in my ITC but they fail when I call the legal department no one answer my calls it rings for ever.all I ask is clarity and communication regarding my ITC