I bought the windows 10 minecraft on the windows store. Is there a way to get the java version without paying another 27 dollars?

No. They used to give you the Windows version if you bought the Java version first, not sure if that's still the case. But it never worked the other way around.

If you call Microsoft they might give you a refund for one you got from the windows store. Just tell them it's not working and ask what they can do about it. https://support.microsoft.com/...scriptions