Cheaper vbucks Method?

Hey Guys, I got my xbox back, and im trying to get some cheap vbucks.

Argentina method with my old account doesnt work for me.

So i tried to make an new account created in Argentina with vpn.
But if i try to login in fortnite it says me that an account is already linked.
How can i "bypass" this? I know the sellers can also login without removing the linked xbox account.
Maybe some one can help me.

Thanks.