Cancel your card, the fee is small enough that it won't be worth their time to actively pursue you for it.
EDIT: I should append this with "It Depends"/YMMV/Do this at your own risk. Based on my years working in and around the collections space, I can say with a fairly high degree of certainty that you will most likely not be pursued in a meaningful or enforceable way for a small amount like this. But then again Adobe might sell your "debt" to someone who will choose to pursue you heavily for it in the hope that they can find a court to agree with them.
EDIT: I should append this with "It Depends"/YMMV/Do this at your own risk. Based on my years working in and around the collections space, I can say with a fairly high degree of certainty that you will most likely not be pursued in a meaningful or enforceable way for a small amount like this. But then again Adobe might sell your "debt" to someone who will choose to pursue you heavily for it in the hope that they can find a court to agree with them.