Dstv billing

I had 1 x DSTV PVR decoder and 1 x holiday home decoder. I use to switch my PVR off, when visiting my holiday home. That would result in no extra cost. Now upon numerous calls to update my PVR to a the latest version of decoder, it is no longer possible. I have to pay now for 2 decoders, if I visit my holiday home. They said that because it is a 24 month contract, it can not be switch off. This was not explained during the promotion, and I would like to know if you could assist me in this problem. I will still only watch one tv at this time, but see no reason to pay for 2. I believe it is hidden cost not revealed when upgrading.