I suspect that the problem was the mass message deletion that happened last week. All notes that were sent on Apr 19 and 20 have been lost.
My advice, as an editor, would be to send a message to the editor who sent your quiz back - you can get the name by looking at the quiz history, on the edit screen of the quiz. Let the editor know what is happening, and ask for some help.
Of course, chances are the editor can't really remember offhand what was written. So, another way of dealing with this would be to take a look at the guidelines for that category, to ensure that you have followed them. Then, proof read your quiz very carefully, looking for errors in spelling, capitalization, punctuation, etc. Then, just resubmit. It is most likely that it was sent back for some problem with the above, and if you fix it up, things should probably be fine.