Thank you for your reply. It is in the proper section, as those sections are more for statistical purposes. I understand your intellectual property issue and am in IP attorney.
First off, if you bought rights to a song then you need to have proof of that purchase of rights in writing. If you purchased the rights from someone you in good faith believed owned those rights and you had no reason to believe otherwise, you are not going to end up liable for violating the copyright for using or distributing the song or material. The person who sold you the rights would be liable to the real owner of the rights.
Second, if you are found to be violating the copyrights because you purchased from someone who misrepresented their rights and could not sell them to you, the court would penalize you by stopping you from continuing to use or sell the infringing material, but monetary damages are not likely against you, they would pursue the 3rd party who sold them to you.
The proof required is a contract
stating that the person who sold you the rights is the owner of the song and that they have sold you the rights to use the song or distribute the song as you choose and it needs to be signed by the seller. That really is the only proof you could have.
As far as who may have reported you, there are companies that search for infringement and also someone may have seen it and notified the true owner, there is no way to really know unless they tell you.
You can get out of the situation with proof that you were the victim of a fraud if the person who sold it to you had no rights to sell it.
As far as attorneys, you are going to need to find an attorney in one of the major cities near you who specializes in intellectual property and you are not likely to find one in your small town. You can find one at the same sites used by other attorneys, http://www.hg.org or http://www.lexmundi.com
If you are truly an innocent user/purchaser, then you should be able to get out of this and sue the person who sold it to you for damages.