I recently tried the full version of photoshop, and cancelled it on day five of the 7 day trial. They offered it to me for 3 months, free. I said "Awright, I'll do it." After two weeks I decided phtoshop was simply overkill, and cancelled my "free" subscription for 3 months.
I had to pay an early termination fee. For me it was $18 and some change (It's 50% of the remainder of your subscription).
I jsut wanted it to go away,so I paid the money, and chalked it up to experience.