Site is back up. Despite the refund, as a gesture of goodwill, you can keep your license.
Regarding wpStoreCart 3. It's not production ready, as we unfortunately found out first hand on May 1st when we installed wpStoreCart 3 on http://wpstorecart.com/ which forced us to take down our site as we could not migrate back to wpStoreCart 2.5.x once we upgraded to 3. If we would've released what we had on May 1st, it would have been even more of a disaster than this whole situation turned out to be, but we certainly apologize for the unusual circumstances and our lack of communication during the situation.
Rest assured, it's been nothing but 10-12 hour days, 7 days a week since May 1st, trying to get wpStoreCart 3 ready for production use. We're happy to have relaunched our site this morning, and it is powered by wpStoreCart 3, so it's at least usable for digital only stores in it's current incarnation. However, there are some major issues that need to be tackled regarding uploading not functioning. So while I'm not going to repeat the mistake of committing to a specific release date, we will be releasing a "tech preview" of wpStoreCart 3 that is for Digital Stores only, and from there we will be releasing nightly builds. Once we get shipping in place, we'll start calling the releases BETA, and then we can shoot for a more realistic launch cycle.