You waited 5 months to address $17,000 but you couldn't wait more than two minutes for a response here?
Anyway, no, the DOL won't sue on your behalf. It may have other methods to punish your employer, but if it can't get the money for you, you'll probably be on your own.
Why haven't you asked the DOL about that?
And why haven't you done anything about this sooner than 5 months of lost earnings?
Heck, I'd have hit the unemployment office the first time a paycheck wasn't forthcoming.
Must be more to the story than you have told so far.