Please check the original character it was on and your vault. Do so in-game. If the item is not on the character you were sending it to, it is either in the Vault (because the character you were sending it to didn't have enough room) or it's on the original character (because your vault didn't have enough room). Items transferred from one character to another go through the Vault first, and not having room in a location or a move order not being fully done could cause the item to be in the previous place, but the Apps aren't always smart enough to update properly immediately after such a failed attempt. The apps don't have the ability to delete an item. It will be in one of the locations.