SPRINGFIELD — When Carl and Jane Hill learned how simple it was to receive unclaimed cash, they jumped on the state treasurer’s website to see if any of their money was sitting unattended.“[Jane] found there was a life insurance dividend for $664,” Carl Hill, of Champaign, said at a state treasurer’s event Tuesday. “I found my name and found there was a $50 rebate that was owed to me. Apparently the money was originally sent to an address where we used to live and was never received …