The good news, (if there is any !!), is that having paid the PCN and release fee, you have paid all there is to pay, and could get all or some of it back. You first appeal to the council, and when they reject, (as they will 'coz they don't want to lose the money), you register an appeal at the Traffic Penalty Tribunal. There are no extra costs in going to the TPT. If you lose there you just lose, and the council keep the money already paid, nothing more.