If you have the time and money for something unlikely to get results for you specifically you could always try suing the person or persons impersonating you in

If you have the time and money for something unlikely to get results for you specifically you could always try suing the person or persons impersonating you in filling documents with the federal government, then subpoena the only known party (FCC) to have information capable of helping to identify that party. Not sure how much good it would do though.