********ly termination of service

About 3 months ago I received a call about my upgrade suggesting if I upgrade I would get 5gigs data for the first three months of my upgrade as a promo deal then I did upgrade only to receive a ridiculous bill after 2 months so I inquired with telkom and was advised they would escalate the matter to their back office it had been an error on their side the billing was incorrect and I will be contacted shortly, after countless calls and visits to their stores I have been messed around and promised call backs an yet no one has contacted me since, after that my service was suspended now completely terminated I am truly disgusted by the level of service this company has offer me and I have been with them for the past 4 years now and this is how the treat me.