Override the switching of theme when prosite trial expires

In this thread https://premium.wpmudev.org/forums/topic/pro-site-what-happen-after-subscriptions-end#post-176878

In regarding to using prosites' premium themes module, Arron, the prosites dev, said when a user's trial expires:

"It reverts to the default theme, either selected by our default theme plugin or the WP_DEFAULT_THEME define (which if not set I think wp uses twentyeleven)"

We're using "pay to blog" so it's confusing when the user logs in, reinstates his plan, he has to then figure out how to get his theme back.

I like the ability to only let certain levels get access to certain themes but since pay to blog is installed and we don't offer a free plan, it doesn't make sense to kick them off the theme since no one can see their site anyway.

Is there any way to override this behavior? I just want them to keep the current theme they have if their trial expires. The only way a theme should change is if they change it.