What options do I have when I was sold forged autographs?
We cannot give legal advice, and are not forming an attorney-client relationship with you. The following is not a substitute for the advice of a local attorney. But we hope the information will be useful.
You are out of options - except for the option of a lawsuit. If the amount of money you lost is significant enough, you will have no trouble obtaining a lawyer. If the amount is small, you may not find a lawyer willing to take the case - unless you pay him/her up front, which would be more money than you lost in the transaction.
You put your documentation into evidence where the guy claims the sigs are authentic, and have your expert testify that they are not, and the reasons he can determine that. Then the jury decides in your favor, we hope, and you are compensated by him in the amount you lost, plus perhaps attorney fees and punitive damages if you can prove the guy knowingly lied to you - but that would be tricky. Call a local attorney and discuss the case.