After upgrading my daughter to an 11 Pro, I wanted to replace the battery in her 8+, as it was at 74% capacity. There are local services that can do it, but the nearest Apple store is 3 hours away and I would prefer Apple do it. I spent an hour and a half on the phone with Apple trying to resolve the issue of the 8+ serial number not being recognized by their system online. In the end, after a call back the next day, I was refused service based on my not having the original receipt of purchase for the device. I bought it on Swappa in November ’17 and it had AC+ until 11/19. I had it replaced under AC+ in the spring of ‘18. Why they needed a receipt for a device they actually have, ¯\_(ツ)_/¯, but I just wanted to give them more $. Slightly annoyed at the time wasted.