Slightly different, but Adobe got me with an unintended annual renewal. For their annual plan billed monthly, there's no way to turn off autorenewal until the 12th month without losing access immediately and paying a penalty. They do send you reminder emails, which I missed, but it struck me as pretty abusive to require an opt-out exactly 11-12 months after signup to avoid being locked into a new one-year contract, with no way to opt out early. One of many forum threads about the policy:
https://forums.adobe.com/thread/2536257
Ugh, I remember now how gross that felt at the time, to realize I was locked into the contract, couldn't cancel, and that the same thing was likely to happen again next year, because they built it that way on purpose. Blech.