INCORRECT BILLING AND INCOMPETENCE!!

I am appalled by the service I received from the Telkom call centre! I have a huge issue and I expected help! On 2nd of March I requested the unlimited Telkom mobile to Telkom mobile which is an extension on the contract for R49 per month. I called the call centre and was told to activate it from my cellphone by dialling a certain number, which I did, but then I called the next day to enquire from Telkom call centre if it's been activated and it apparently wasn't. I was then told that they can activate it for me and put a spending limit of R50 on my account to cater for the R49 unlimited Telkom mobile to Telkom mobile calls. I ensured and it was confirmed that it will be charged at R49 per month. It was then activated by Kelwenyana. I was billed this month for R99 for March and R99 for April PLUS R49 each for these 2 months and the reason?? BECAUSE I ACTIVATED IT FROM MY CELLPHONE AND ASKED TELKOM CALL CENTRE TO ACTIVATE IT AS WELL!!? I spoke to a Thembeka Myeza who also confirmed that my records provided that I had requested the R49 service, then emailed me to tell me that she spoke to her manager and says that I am liable for the payment as I activated this service. All this time I keep asking for her manager and supervisors details or someone I can speak to in a higher position who will attend to my complaint, but to date I have not received feedback from her. I want to know, how do you activate ONE service TWICE? It is only on ONE contract how can it be activated TWICE simultaneously on one number? I had told Thembeka (on 26th April) to cancel all these services on my contract save for the amount of the contract itself of R350 and she confirmed that everything has been activated. Then on 1st of May I receive an sms from Telkom saying that my account is provisioning with unlimited Telkom mobile to Telkom mobile calls and minutes will expire at the end of this month and that R49 was debited from my account?! I HAD CANCELLED THIS SERVICE ALREADY!! I am very very upset about your level of service and the attitude and feedback i receive without an investigation into the matter, especially the fact that I am being billed twice for one service and of an amount of R99 which I never requested! I therefore ask for this matter to be looked into and a solution found as well as a refund of the extra amount for these 2 months as well as a number of someone I can liaise with in regard to this. I shall be taking this matter further if I do not receive my money back.