David, can you give us an approximate time-line....
- How long was the old site down before the new site went up?
- How long has the new site been up?
- Does the new site have any inbound links? Ie, are any sites now in Googles index linking to the new site?
- Is the content on the new site currently the same or different from the content on the old one?
Note that phranque, whose post immediately follows yours, asks a very important question, which would be helpful to have answered....
if the site is unreachable it should eventually drop out of the index.
what response do you get to requests?
We don't know how much you do or don't know about webmastering... so please forgive this explanation if unnecessary... The "response" phranque mentions is not merely what happens as observed by the eye... He's asking about something technically specific... called a "server header response", using a tool called an HTTP Status Code Checker to report on various technical issues that might give us all an idea what the status of the old domain currently is. If you don't know what status codes are, perhaps someone can talk you through how to find and use a code checker.
(I'll be unavailable for most of the rest of the week, but thought I'd jump in with these questions).
Good luck. It's not a nice thing to have happen.