I went through a similar experience - in fairness Adobe do say that the prices advertised are the monthly fee based on a 12 month subscription, but the way in which it was presented felt like they went out of their way to hide that fact.

I then discovered that you can only cancel that 12 month subscription within a short window at the very end of the 12 months.

In the end Adobe retired one of the products from Creative Suite and I used consumer protection law to cancel the subscription on the basis that the service had been materially changed.