Cell C
Coverage problems

No Coverage @ Drakenstein Prison in Paarl near Franschhoek can't use my phone to make a call or sent sms,
saleslady @ Cell C Paarl Mall inform me to change from Cell C to Vodacom??? We are lots of people @ Drakenstein Prison and all off them have the same problem with Cell C Coverage... Please can somebody help us??? Can't use Whatsapp, Facebook, emails whats the use of Cell C...