more payment from me with no services

Telkom decided to bill penalise me for debiting on the wrong date and they refuse to take responsibility and they decided to suspend my services with no valid reason. they claiming that i owe them R450 which they cant explain for what is it for . managers of call centre refuse to take my calls after i have requested to speak to them several times. Can anyone assist me with Sereme Taukobong contact details or should i just go to their office in centurion