I will be sending an email to the ceo but my appeal deadline with Athena ends tonight so I am not too sure of what to write in the appeal. Are you able to help me with this? Thanks

I accidentally overstayed by 28 minutes in a Lidl car park in Leicester and so my father (who is the registered owner) was sent a parking charge notice for £90 (reduced to £45 if paid within 14 days). I need to appeal by today but have no idea what to say as I have never received something like this before and I do not want my father to have numerous notices sent to him so what can i do? The signs are not very clear at all in the car park and are just dotted around and you would only really be able to see them if you parked in the spot directly in front of the sign however, I have no pictures to back this up as I no longer live near the store. Can anyone help me with this please?!