Adding device charge without permission

I renewed my Cell contract about 6 weeks ago via a call centre at Autopage Sandton. Now suddenly I've receive a massive bill with an additional \device"charge added to it. I've never agreed to this. I agreed to a package of R499 which included the handset. Now I've been informed (after speaking to 6 different people) that because I renewed my contract early the additional \""device charge\"" will be added to my account for around 5 months.<br> This was NEVER stated in ANY conversation or ANY agreement WHATSOEVER with Autopage. Doing this is simply ***** and also ********* and not what I agreed to. I need to have this cost removed off my account immediately."""