Shokcing Treatment for something I did not choose

I have been receiving SMS's from edgars saying I need to pay my account which is in arrears. Suddenly I receive an sms saying they are going to hand me over for debt collection. I have not used my account in many years and suddenly I owe money. When I contacted them I had to speak to four different people in four different departments telling me I chose an airtime product. It is shameful to be treated like this when I have always been a loyal customer and I never chose any product with them. I have a Vodacom account so why on earth would I choose an airtime product. NO one phoned me to inform me of this product and where the hell did the supposed airtime go which I never even received. I never chose any such product and needless to say it has not been sorted out, however I will not pay any such money for something I did not choose and edgars can hand me over I will keep on fighting this. I will also be closing my account after years of loyalty as I do not deserve to be treated this way.