i recently purchased dark souls 1 in the steam sale and it runs on windows live. i forgot my xbox account email as i used to have 2 but one was permanently banned. i accedently redeemed the product key on that account and it wont let me redeem it on my main account now as its been used however i cant use it due to it being banned. what can i do?

also i cant rebuy the game on my steam account as i have already purchased it, any help please????????????