Another Parking Eye Invoice question

[W124Bob]

My wife used a leisure centre car park which is free to patrons but requires registration input at reception, she didn't. Two weeks later I receive an invoice(as registered keeper) usual "Pay £60 now", my wife takes this to the leisure centre reception who agree to email PE to cancel. As you can guess a second invoice arrives on the final day of the discount period, this time I take it and speak to a manager. He takes my email address (along with the same from the woman in front of me) and copies me in to his reply to PE. I have that request from from him to PE asking for cancellation. Today another invoice from PE with a demand for £100, to complicate things the centre is now closed. Any advice please, just to add no direct contact with PE has been made so far.

[Blanchimont]

I would email them to appeal, including a copy of the cancellation request from the leisure centre.