NCP for Gatwick is a complete scam. Tried to pay repeatedly but their system just kept buffering and wouldn't proceed to payment. Called the number twice and they can't help over the phone but advised to wait for the PCN and appeal saying I tried everything to make payment but it was a system issue. Received PCN on 26th June, filed appeal at 20.53 and at 2.41am on the 27th June, a generic letter was sent saying that they had reviewed and it was declined the fine still stood. Legally, appeals need to go through a process and it definitely wasn't carried out in this case. Scam merchants.