> Twitterific should be pro-actively refunding customers for the unused portion of their subscriptions...
It's my understanding that Apple doesn't offer this feature.
This is correct, they couldn't do it if they wanted to.
Sometimes Apple Dev Relations will help out and mass refund without making all the users request a refund, but they don't always (even when the developer asks).
Twitterific made a bet that the Twitter API would remain available to them. They should be the ones assuming the risk and taking on the consequences of losing that bet. Not their customers.