It is probably my own fault, but thought I'd post this to raise awareness in case there are others like me who didn't know 
I had an annual subscription to a magazine. I cancelled the dd before the renewal was due as I was bored with the title.
I found today that the magazine publishers just raised another dd and took the money. Apparently, this is within their rights.
I've asked nicely if they will refund, but am a bit miffed.