If they cashed your check and didn't send you anything (not even a note to say they couldn't find the grave?), then you should report them to the local Better Business Bureau or their local Chamber of Commerce.
I didn't find a Warren County Genealogical Society but there is a Warren County Illinois Historical Society, www.warrencountyhistoricalsociety.net/
If you're sure that isn't where you sent your previous check, I'd contact them.
If that is the organization where you sent your previous check, you'll have to wait until a FAG volunteer takes a pic. Successful Searching!