Hi. Thanks for your report. Unfortunately, if the error message says that your Steam account has already been migrated, it's not possible to migrate to that Steam account again. To migrate, you will have to unlink your Steam account in your [url=https://www.bungie.net/en/Profile/Settings]Bungie profile settings[/url] then link another Steam account that hasn't been migrated to yet.
I understand but the Support itself wrote to migrate to effect, as a result of which each of us failed to migrate to our Steam accounts. And as a result of Bungie and Support mistakes, are we to set up new accounts specifically for one game? Why can't the support or technical department clear the migration history or something similar at the user's request? Is it possible to return the money for the game and all add-ons that I bought? This would allow me to buy extras from the Steam level in my Steam account. For the clarity, I'm not angry with You Bungie Supporter just about the whole situation.
I understand your frustration. It is not possible for us to clear migration history - once an account has been migrated it's impossible to migrate it a second time. If you would like a refund, you'll need to talk to the platform that you purchased the game on to request it.