When you exit the Autostrada and arrive at the barrier to pay, push the 'aiuto' (help) button to speak with an operator. Technically, you are required to pay the toll for the earliest entrance you could have made. A way around it - tell the operator where you entered and pay the appropriate toll. From there, you have two options to avoid paying the rest of the toll: 1. Go to an Autostrada PuntoBlu and give the attendant your car license plate, where you entered and exited, and the approximate times. 2. Go to https://www.autostrade.it/en/rmpp/ and mail or fax back (within 15 days) the self-certification form with the same information from option 1. You'll have to pay a small administrative fee for both options, but if they can find your car's entrance and exit on the video footage, they'll wave the large toll.