Allo there, Unfortunately nothing can be refunded or granted. You had over a year to transfer your characters and licences. Keep in mind that the deluxe at the time contained the base game and first 2 dlc as well as other goodies. The base game and first 2 dlc were made free a long time ago and have since been removed from the game. So if you start again on Steam you wouldn't be able to access those locations even if you did transfer your entitlements in time.
First off, your purchase was with Blizzard, so any refund requests will have to go there. Bungie is neither responsible for battle.net- nor steam purchases and therefore can't grant any licences. Besides, even if they could, they would not. You had about 1.5 years to transfer your purchases from blizzard to steam for free. This time ended in december 2020 and now it is too late.