Blizzard complaint: Account hacket, charackter being moved from vanilla to wrath classic

I have been playing WoW for 15 years (a bit on and off). Now I’ve found myself in a situation that makes it impossible for me to return unless the following issue being resolved.
I played WoW Classic Vanilla and had several weeks/months of playtime on my character.
In April/May 2020, my account was hacked, and as a result, I lost access to the game I love.
A friend told me I could contact Blizzard to recover the account, so I submitted a ticket.
It turned out that my characters still existed, and I was overjoyed. However, this happiness was short-lived when I discovered that these characters had been moved to Classic Wrath, not Classic Vanilla, where they were when I got hacked.
I have an ongoing conversation with a GM from Blizzard, who states they can’t do anything about the situation.
I won’t accept this, and that’s why I’m reaching out to you here, because I’m kinda desperate.