Rewards competition with ts& cs not clearly defined

I've been a subscriber for many years. Each year I want to cancel my subscription, however I just don't get around to it. Recently and perhaps this was one of the reasons why I didn't get around to canceling my subscription. To cut to the issue at hand. I recently won an upgrade. All excited as I'm currently on a family package. And the prize was to be upgraded to Premium. Only to be disappointed when I enquired about it. I was told that there were *ts&cs" linked to the prize. Very disappointing.