Paid for service not receiving

Dstv updated my subscription on my behalf saying will be for free for a month and will be downgraded after a month, but now every month they switch off my decoders wants me to pay extra which I am not going to pay, I engage them of Facebook they responded with reconnecting the one that was off and disconnected the one that was active. All of the are fully paid. Please assist sk that I can get services I have paid for pr get my money back.