Was automatically registered for an annual subscription after 7 day trial ended- had to pay $30

I went to cancel my "free subscription" with Adobe (which I didn't event end up using" and had to pay $30 USD (I'm in Canada so more like $47 CAD) to "cancel early" for an annual subscription that I had automatically signed up for when my trial ended. How is this possible?? Adobe needs to make it much more clear that this is what's going to happen - at least a check box to acknowledge you understand you will AUTOMATICALLY BE REGISTERED FOR AN ANNUAL SUBSCRIPTION AND NEED TO PAY AN EARLY CANCELLATION FEE if you don't cancel within the 7 days. That's absolutley ridiculous and I cannot believe they're able to get away with this. I will never sign up for an Adobe trial again - robbery!