It's legal, you just still owe them the money. Nothing is stopping you from canceling a debit card that you have active reoccurring payments on, just if your mortgage was one of those the bank can still find you in default.

Similarly if Adobe owed you money they may make you run through a customer service maze in order to get it. That's legal too. They don't have to provide you with a method to automatically take as much money as you assume you are owed.

You left out the part where they sell the debt you have with them to a debt collector who will then ruin your credit score.