When subscriptions are expiring, I see that they are no longer marked as "active" for the expired user, however their primary usergroup doesn't change and thus the user still has the same level of access they had when they had an active subscription. I've been using subscriptions of close to 3 years now and I don't know if this has always been the behavior (and apparently my users have been very nice in renewing their subscriptions every year).

So my question is this: When a subscription expires, what can I do to ensure that their access changes? Ideally I would like the primary usergroup to change to an unpaid usergroup.