Domain theft

You can file a complaint with ICANN about the registrar, but that typically results in no action. GoDaddy is huge, and especially immune. I would try to reach someone higher up at GoDaddy and ask again, but failing that I think your best bet to get the domain back is to file a lawsuit against GoDaddy and the current registrant. You're probably looking at a couple thousand to get the lawsuit rolling, unless you're a serious do-it-yourselfer. They may settle at that point, and you may recover costs as part of the settlement terms. If not, a rough estimate would be $50k-$100k in legal fees and a year or so before a decision would be reached. If you're successful, the judge will provide the court order, which you can then provide to GoDaddy. I'd give your attorney a copy of their registration agreement, so she or he can determine if legal fees or additional damages could be recovered in the event of a successful outcome. GoDaddy's domain transfer system is bad enough that I think you'd have a good chance at proving negligence.

just transfer it back to your account.. even if he turns it down, godaddy will still give it to you.. I mean, that's how you lost it.

lock your domains.