I have been in this situation where the client asked for revision without any details. I requested details for a week or two but got no response. As per the TOS, we can't deliver same file. The delivered file after the client asks for revision must contain the requested changes. So I contacted Customer support. And it got resolved. within a few days, he replied and we were on track. :)
Don't worry once you deliver(first delivery) it's not late.