Cell c have a very bad service

I have a contract with Cell C.. I never ever gave them problems, from December last year they stopped debiting money from my account and suspended my account... Thy then called me then we set another date for debit.... Still they di not... And still now we having a same problem wher they dont debit and they tell me my account is in arrears... I took initiative last month a phoned them to please debit the money... Still it did not happen, its their fault they don't debit the money.. And i refuse to pay the arrears... And their consultants don't have answers to our questions... And choose to hang up on us which is vwry rude for a big company like cell c