Unauthorised subsription and refusal to close account

I recently received a statement from Edgars stating that I owe R50 for an airtime subscription. This subscription is apparently with a third party company called RMCS. I did not authorise this at all because I have no need for airtime as I am a contract subscriber.

I paid the R50 in order to make the process of closing the Edgars account easier. The consultant I spoke to at the time said I need to e-mail the proof of payment to the relevant department who will then close my account and in doing so automatically cancel this unauthorised subscription.

This morning I called the Edgars call center again as I have received no feedback on the closure. The consultant advised me that I need to personally call RMCS to cancel my subscription before she can close my account. I advised her that I refuse to deal with RMCS as I have tried in the past and they didn't even answer their phones. She then put me on hold for a few minutes and eventually hung up.

My questions are: a. How did an unauthorised subscription get on to my account? b. How as the company billing me for the above subscription is Edgars unable to assist me with this problem?