A contract I cannot get rid of!

I received an SMS from Edgars offering R50 airtime for R25 for six months. I agreed to it. The six months are up and I cannot stop the airtime. I have tried to cancel it twice, I have received two sms's to say that the cancellation call has been logged and my account will be credited. My reference number is EDCN ***. I spent about 20 minutes on the phone with the call centre at Edgars with the person telling me I can phone this other company that the airtime is with, to cancel. As I pointed out to him, my account is with Edgars, I received the SMS from Edgars, I received the bill from Edgars for the airtime. I did not have a contract with this other company. I agreed to it with Edgars. So I am not phoning some other company that I have never heard of. <br> Now I just received my bill this evening and the airtime is added AGAIN! HOW DID I GET RID OF THIS DAMN AIRTIME???? Edgars is doing nothing to sort this out. And I am so angry that I am now involved with what appears to be an inefficient or ************ (not sure which yet) company that does not stick by their agreements. Edgars, SORT THIS OUT!!!