Technically speaking, Nafun, our Support Staff wouldn’t directly assist in any of those situations as there are systems in place for it. If you deleted a character there is an undelete option, if you destroyed an item there is an Item Restoration system and now Character Transfers are available for those who wish to use them.
Prior to the introduction of the Paid Character Transfer option, we would not be able to help outside of those Free Character Moves that were previously made available.
To be clear, you weren’t told simply to reroll, but if you absolutely must have the item that you were going for on a quest that you already completed, yes, that would be an option.
I’m not sure how that compares, Nafun. You admit you made a mistake, but the reason we don’t fix that particular mistake has nothing to do with the other two items.
In Vanilla, Game Masters would help when a player accidentally deleted, vendored or disenchanted an item. We now have an Item Restoration system that allows players to do them for themselves. There is a cooldown associated with the system so that players can fix the occasional mistake without using it a means to be careless with item interactions.
Character Transfers is a service that was introduced originally in Vanilla and something that was requested. Nothing to do with your request at all.
Our Customer Support staff is there to help in many cases, but support for Classic is limited by design. An outline can be found here: WoW Classic Customer Support and You
If you would like to see policy change about how we handle player error regarding quest item choice, you will want to submit your suggestions via the in-game option in the help menu or by posting in the WoW Classic General Discussion forum so our Devs can review and take the request into consideration.