I have a bit of a problem here as I have accidentally deleted my treasured "Arcus Cloud" mount when I was clearing space in my backpack. I was deleting 1 day and 7 day mounts that I had obtained from packs. Now, I know it is my own silly fault for not 'locking' my item and the same mistake I can assure you won't happen ever again, but I would really, really like my mount back I am a long time player of wizard101 (I've been playing for 7 or 8 odd years) and spent countless amounts of hours (and dollars lol) to make my characters the way I want them. The "Arcus cloud" would be the last thing I would want to get rid of for my storm wizard. It completes my look! And I understand this story may seem a little sketchy. However, I paid for that item with my hard earned money and I would be very upset if I cannot somehow get it back..
The best thing you can do to recover it is to email KI support to get it back. They are able to restore items sometimes, under certain circumstances, so they may be able to get your mount back.