So I didn't buy the monthly pass, and now can't use the store. Is there anywhere for me to get Koban?

I'm so sad about this game closing. I started playing this game around release, but not very frequently. I spent like 200 bucks on summons early on, and didn't even know about the monthly pass until a few days ago. The fact that U EVO cards are only 100 koban, and I have no koban or monthly pass is so frustrating! I know there's less than a month left, but I usually don't play this game for more than a few weeks at a time anyways, and wanted to finally make a good team.

So there won't be any way to play this game after april 22? No offline version or anything?