Please help me on the matter above

Good day, i am currently having a challenge with on Airtv. Two months ago i was called by an agent from on Airtv to sell me two explorer decoders for R199 monthly, including the rewinding, pause nd recording. The second decoder being an extra view. Saying that all the functionality are included in that montly instalment of R199. She was so adamant to make a sale, saying that if i dont want them i can return them, she gave me her name and employer no. They sent the decoders with a courier guy, sent their technician to install them. Come month end i owe Dstv R800. I called on Airtv to tell them that i dont want it any more as the person who sold them to me said i could return them if i am not happy with them, told them to cancell my debit order nd they said they will not debit me. But no one knows what must happen to those decoders. I dont know how many times i have called them to get clarity, no one knows how to help me, they always transfer me, and never get help. The other time i called they said i must go to a walk instore in the mall of the East. On the 15 of June they debited my account after they promised me that they wont, after the public holiday, i went to reverse the debit order. Yesterday someone from collections called me, i told him my story. As he was transferring me, i dont know what happened and the call was cut off. Please can someone advise me on how to deal with this matter further.