Free Traffic Legal Advice

I parked in a private car park in London that has a 'day rate' not an hourly rate.
It uses the 'pay by phone' app, which didn't work initially on arrival.
As it was a day rate I paid prior to leaving.  For this car park it doesn't matter what time you pay, it still charges you the same rate, and the parking period ends at midnight regardless. The signs do say you should pay on arrival though.



I received a PCN, which I appealed, supplying the receipt for the full day rate. The appeal was rejected as I 'did not pay for the duration of the parking period'.  I've appealed again and will take to arbitration, and I have uploaded evidence that I have paid for full duration of the parking period (the receipt and the parking sign confirming the day rate).  The only breach of the T&C's on the sign is that I did not pay immediately on arrival, although I have given a reasonable explanation for this.

Are arbitration able to uphold the charge purely on the basis I did not pay on arrival, given the rate is not hourly or dependent on the time of day paid?  I usually just suck it up and choose the easy life option and pay their reduced rate, but this car park is adjacent to a hospital and takes full advantage of this to line its pockets from the staff, and their insistence on upholding the PCN when I've clearly paid the correct rate (albeit later in the day) seems unjustified. .

It's with IAS 
I amended the post with the info.  Sorry they've come up massive!
This is what I wrote to them. I realise now coming onto this forum I made several rookie errors in my reply.

I am appealing this parking charge on the following basis
-Full day rate clearly paid prior to leaving the car park with attached files to confirm.

I received a parking ticket for parking in the 'Meridian Sports and Social Club' car park on Sunday 24th August.
This car park has a day rate on weekends of £1.00 between 00.00 and 23.59. When I arrived the 'paybyphone' app was not working, so it was not possible to pay on arrival. I paid the full day rate later in the day, prior to leaving the car park. I received a response to my initial appeal stating that it was not upheld as the ‘Tariff paid didn't cover the full duration of the vehicle stay'. This would require one of two conditions to be met to be true:
1) The tariff was an hourly rate and not a full day rate. I attach the signage from the carpark the confirmation of payment to confirm that this is not the case.
2) Paying late would confer some benefit such as covering a longer period than it would have if I paid on arrival. The confirmation email I received (attached) clearly confirms the parking period ends at midnight.

The attached documents clearly prove that paying late made no difference to the tariff, and that I have paid the correct tariff to cover the
duration of the parking session. Regardless of at which point in the day I paid, the tariff was always the same. Yes I did not pay on arrival but this was due to a problem with the app, and made no difference to the rate on this day. I did pay before leaving the car park.

I therefore believe that I have supplied sufficient documentation to contravene the statement that the 'Tariff paid didn't cover the full duration of the vehicle stay', upon which my initial appeal was rejected.

That's really helpful thank you, really should have come here before putting through the appeal.

If the IAS uphold the fine, is there any avenue to complain about the PPSCoP breach? Do I then just have to either pay it or argue it in court?

Update: After appealing to the IAS the parking company decided to drop the PCN.  Thanks to anyone who took the time to reply, it's a really helpful forum