Cell c avoid them like covid

Pathetic service from Cell c, Billing department is ran by grade R. Have a month to month fiber with cell c pay my bill every month send them the proof of payment. Finally on the 17th they cancelled my line. I logged a call sent all proof of payments and all my invoices including the last invoice which sows a cancelation fee ect. but no months that out standing. they now refuse to release my line as they say i owe them 4month and all proof of payments have been sent including all invoices that never show any outstanding amounts. NEVER USE CELL C the worst