If the title were not clean--that is, if there was a lien on the vehicle--then you would sue the prior owner for breach of contract (he did not sell you what you paid for) and/or fraud (he made material, or important, misrepresentations, or lies, in selling you  the vehicle). If the title were clean and the vehicle were taken improperly, you would sue the recovery service.Legally, they cannot hold onto your personal belongings; practically, there is no way to get them back without suing. One option is to file suit against them for your car's return, which will force them to turn over your belongings and, more importantly, prove in a court of law that they have legal right to the vehicle--and if they don't you should get the vehicle back. Then if they do have legal right, you might then sue the seller. It would be best, however, if you retained an attorney to help you with this case. An attorney will almost certainly know to verify who in fact does have the legal right to the vehicle, and how best to proceed against them.