The only way to delete a character is manually doing it and an error code won't do that. Sounds like you were kicked and someone gained access to your account and deleted your characters.
I suggest you change your passwords and enable 2 factor authentication if you've not already.
Unfortunately Bungie can't restore any deleted characters or weapons.
[quote]Bungie does not provide the following services:
[b]Restoration of deleted characters[/b][/quote]
[b]Recovery of dismantled, scrapped, deleted, or otherwise discarded items[/b][/quote]