To my understanding, the only thing you can do from there is either:
1. /petition a GM
2. PM a GM on the forums (usually Rizin IIRC)
3. Find a GM on irc
There is no automated process for getting this back right now that I am aware of. However, certain NPCs (as long as I have not received an item or already been dismissed by them for whatever reason) allow me to use the same key phrase to get them to start over. I usually have to do this when I get frustrated with them, get attacked by a rogue, then have to go back to talking to the NPC. So, for instance, "Jayose sent me." being the key phrase, if I say it again in the middle of their rambling speech on clacker reproduction or whatever, should start it over if I haven't already received the book on clacker lifecycle.
*** This is not a reference to any real IG quest that I am aware of... only for illustration. ***