I cancelled my viewing passes and have been buying them from amazon as it works out cheaper. I went on today to find out when they are due to run out only to find that they have been renewed without my knowledge. WTH. Really short of cash this month and could have done without this.
You must cancel a pass after succesfully entering a voucher number in order to prevent any rolling subcription charges.
You said "I went on today to find out when they are due to run out only to find that they have been renewed without my knowledge."
So you didn't cancel your pass in time. That's your fault i'm affraid. It clearly states within the terms & conditions, on the passes & vouchers page as well as the voucher you purchased that you will be charged a standard monthly fee if you do not cancel before the pass expires. You could try live chat but if you've watched any content for the period you were charged for then you likely won't get a refund. :/
First, let me say that Paul's advise, from my understanding, is quite right.
However, I just want to mention that the way I keep an eye on my passes, both Cinema and Entertainment, is to note their start and end dates and, most importantly, their warning dates, i.e. the date when I must either renew or cancel, in my electronic diary.
As most personal devices have diaries installed, I would suggest that this would be the best way to prevent yourself from being caught out the future.
You see, I, myself, have found that nowadays I cannot rely on just my memory, and so I've press ganged my e-diary into daily use.