What is the etiquette on buyers changing their mind after winning an auction?

[cbr600rr3]

What is the etiquette on buyers changing their mind after winning an auction?  I have just sold an item, that was listed for 10 days.  The winning bidder emailed nearly 24 hours later and said her mum has bought one so no longer wants it.  It is a polite email.  However, that means I have to relist it, and wait to send it again.

Do people just cancel it, and move on, or do people start an unpaid item case?  Any advice, greatly received!

[plpmr]

you can open an unpaid case or -

https://community.ebay.co.uk/t5/Announcements/Buyer-requested-cancellations/ba-p/6676564

[cbr600rr3]

Thank you, I followed your link and copied what Ebay had said, to the buyer, but it has come back to her to say it is too late to cancel. So I'll just have to cancel it my end.