Trial members not dropping down to 'Subscriber' role after trial ends.

Hello,

We offer 30-day trial memberships yet when the trial is over, our members are still listed as 'Crushtrader Members' for their user role. They *should* be dropped down to 'Subscriber' level (default) so that they do not have access to any premium content. This seems to work (or not work) intermittently.

I'm not sure what the default behavior of the plugin should be but we would like for members to lose the premium user role status when their trial ends. Is that possible?