Euro Car Parks - overstayed the maximum time period allowed

We received a Parking Charge Notice (PCN) relating to our vehicle at Sainsbury's in Ilford, Essex. It alleges that "your vehicle has overstayed the maximum time period allowed", but we could not see any clear signage stating what the time limit was.

The vehicle was parked in a Blue Badge bay with a valid badge displayed, and shopping was done in the store during the visit. The photos below show the only sign we could find in the car park. Any advice?

If that is the only sign then the driver cannot form a contract with a timeframe that is not visible. The terms and conditions do not specify how long you are able to park for.
1. You can go to Sainsbury and request cancellation but I do not know how long the driver can park there. If it transpires that there are signs they’re providing a parking time you can request a reasonable adjustment be made for the stay.
2. The Registered Keeper can go straight to the Parking company with a lack of signage being displayed as I think they may provide signs with far more details that is only my opinion. Again the driver can use the reasonable adjustment under the EA.