What BD needs to do is put up a post telling users that the default when purchasing a license is auto-renewal.
They need to mention in the post that auto-renewal can be turned off in one of two ways
1. When puchasing a BD license.
2. By going to Avangate and turning off auto-renewal before the auto-renewal kicks in. I have done this in the past and the procedure is very easy. You create a user account with the same email address as the one you used to purchase the BD liense. Your product page will then show you active licenses purchased from Avangate. From there you can go to all your licenses individually and turn off the auto-renewal.
BD should also include in the post the procedure that users can use to ask for a refund.
While Bd Marketing people may hate the idea of such a sticky post, BD users would greatly appreciate it and it would do wonders for BD customer relations.