Ebay have just changed their cancellation process and it sucks!  We used to get a multiple choice reason for cancellation which you could enter they bought in error, but now there a 2 choices which don't reflect the true reason.  I had same thing a buyer bought 2 items so I contacted him to find out if he wanted both or just one - never heard back.  This went on for a while till I decided to cancel, now those items are still sitting in my sold list waiting for removal.  Ebay have a note on them saying "waiting to see if refund has been given" - that's also incorrect as they buyer never paid & has not responded to me or them.  What used to be a 4 day wait is now 10 days.  They will automatically remove it then, but you can delete it yourself if you don't want it sitting there.  There will be no comeback on you but maybe on them, you don't know if they are in the habit of doing this.  Just block them so they don't have the opportunity to do it again to you.  Good luck 🙂