I have to pay because they cannot find a device they collected

I added a contract to my existing portfolio. I received the device in December 2020. The same day I received the device I phoned to cancel since I was very unhappy with the device as per their own returns policy. Vodacom scheduled a pickup with RAM couriers but couldn't give me an exact date. RAM picked up the device on 22 December 2020 and left a collection slip with the tracking no COL***. I phoned 10 days later as I was instructed to cancel the contract. They confirmed they had not yet received the device. So either RAM or someone in their warehouse stole the device but I followed all protocol and instructions so this is not my problem. They now cannot cancel my order because they cannot find the device and I have to continue paying for the device every month even if I don't have it. I have phoned many times and have a complaint reference number. Every time someone promises to get back to me but no one does. I have also complained on their FB page and the last time I asked for an update the person told me: Once feedback is available it will be communicated to you. Just that. So now I must continue paying till you get your ducks in a row?? How long will that be??? I must just continue to pay?? I need this contract cancelled and the money I have already paid refunded back to me. As per their OWN refund policy. I can see on the RAM tracking service online it was received on 23 December 2020.