I'd give it some time, maybe a few more days to a week before even thinking of doing anything. If they still ignore after a week I would consider naming the person publicly especially if they are still active around the site. Thing with naming publicly is this is kinda a last ditch thing to do and it isn't fun for anyone.
If they are a more active, established member I would definitely give them the benefit of the doubt, things happen, some people just absolutely suck at communication and aren't as courteous as others.