Invoice not approved for countering brand authenticity as 365 + days older

Hi

We're tried to prove the authenticity for a branded trainer, however looks like amazon does not accept it as the invoice is more than 365 days.

I'm sure they can have some consideration as our main business is Wholesale Clearance and have some older items more than a year old. Some of these items go onto our retail channel, but can guarantee it's authentic as we have got brand approval from that same clearance house before.

Is there any way we can submit a letter for this to explain , as an invoice being older than 365 days in there view is insufficient to counter the product authenticity claim.

Essentially that means we need to take off any items that are more than a year old to prevent this from happening in future. Seems unfair / illogical.