Disputes at @stripe are weird. We literally sent them an email from the customer who disputed saying we had sorted everything and she was happy. Result? They refunded anyway.
Really sorry you've been hit with a dispute—unfortunately, even when a dispute is withdrawn by your customer, you still need to go through the evidence submission process https://stripe.com/docs/disputes/withdrawing …. Feel free to reach out to us https://support.stripe.com/contact and we can take a closer look!