Subscription does not revert usergroup

[CrashfAB]

So I am prepairing my forum for paid subscriptions. I have setup my paypal and my subscriptios (4) along with custom usergroups for each subscription.

For testing reasons I created a test user. I went into the user manager and manually setup the paid subscription (using quick user link). I set the end date so I could see the user revert back to the origional usergroup(registered user).

Well the time comes and goes and the user does not revert back to "registered user" instead stays at the paid subscription user.

What am I missing?