Paid up letter not enough prove for cell c

I've been wrongfully blacklisted at cell c again after been removed from their blacklisted after been provided them with paid up letter multiple times . This is stating to being a frustrating experience and the reason why I will take my 2000 rand a month commitment to a other service provider. Who is serious about customer care. The franchises wonderfull service means nothing if there is no customer care or customer care at their legal department.