Amex chargeback through Stripe lost because evidence deadline was missed — any way to reopen or submit evidence directly?

Hi all,
I’m looking for advice from anyone who has dealt with an American Express chargeback through Stripe, especially where the dispute was lost because the evidence deadline was missed rather than because the evidence was considered weak.

I run short-term accommodation and took a booking through Lodgify, with payment processed via Stripe.

The guests stayed at the property, occupied it, used the accommodation, and later voluntarily checked out early. I have WhatsApp messages, Lodgify booking records, checkout/key return evidence, and CCTV evidence showing that the accommodation was provided and used.

Despite that, the cardholder raised an American Express chargeback for around £812 on the basis of “Product Not Received” / accommodation allegedly not received.

The issue is that the evidence submission deadline was missed. Stripe has since told me that the dispute was not lost because the evidence was weak, but because the evidence was not submitted within the required timeframe. Stripe has also said there is no further route within Stripe/card-network process because the card-network deadlines are absolute.

I have asked Stripe whether they can provide any additional dispute references or Amex case details so I can follow up, but I’m trying to understand whether there is any realistic route to:

Ask Stripe to reopen or escalate the case;
Submit evidence directly to American Express Merchant Services;
Ask Amex to record that the dispute reason was contradicted by evidence;
Recover the money outside the card-dispute process, for example through small claims.

The evidence I hold includes:

Lodgify booking records;
WhatsApp chat exports confirming the guests stayed and later left;
CCTV/checkout evidence;
evidence the keys were returned after departure;
Stripe chargeback records;
Lodgify terms and conditions.

The frustrating part is that the dispute reason was “Product Not Received”, but the accommodation was clearly provided, occupied, and used. The only reason the dispute appears to have been lost is that the evidence deadline was missed.

Has anyone had success getting Stripe to escalate this after the deadline, or contacting Amex directly as the underlying merchant/service provider where Stripe processed the payment?

Also, if Stripe says the card-network deadline has passed, is small claims generally the only practical route left?

Any advice from people who have dealt with Amex disputes through Stripe would be appreciated.