Most likely your attempt to purchase a firearm which was denied by the owner of the gun shop will not result in a criminal action being filed against you by the district attorney's office in the county and state that you reside in.You did not make the purchase. So even if you were convicted of a felony and are on probation, you did not possess a firearm which most likely would be a violation of the terms of your probation.I suggest that you consult with your probation officer to determine what you can and cannot do under the terms of your probation.