How do you correct a late shipping report

[magicblackcat36]

I sent my parcel by Royal Mail by the due date but Royal Mail too a week to deliver so I got a late shipping report against me.  I can prove that I posted on time.  How do I challenge this as it was not my fault but the fault of Royal Mail.

[mtgraves7984]

Wow. You've only sold two items... one July 30 and one August 1. It's already in your Seller Hub that you have a mark under 'Late Shipment Rate'? In the US, we're evaluated on the 20th of each month... I don't know how it works in the UK. Dang... sit tight with other posters with knowledge/experience with this. 

[kensgiftshop]

Did you get the package scanned when you dropped it off?