During holiday in Cornwall we visited Falmouth, where the car park charge was £1 for one hour or £2.20 for two hours. I witnessed my wife put £2.20 in to the machine, which produced ticket that I placed on dashboard without checking. We arrived back after about 90 minutes to find a parking charge notice. When I examined the ticket it had registered payment of £2.10 with expiry time of one hour. The penalty was £100 reduced to £60 if paid within 14 days. I set out the facts in an appeal letter, but this was rejected. I sent second letter enclosing a cheque for £10 saying this was more than adequate compensation for alleged non-payment of 10p. My cheque has been returned, saying charges are not negotiable. I have an opportunity to appeal to POPLA but I am concerned that they are not independent. What would you do next?