the dlc code from game stop

I purchased the FH2 from game stop for the xbox 360. the code they gave me for the Lamborghini was for the xbox one and they told me it was the only code they had for this. I have redeemed this code but as I stated it was for the xbox one. I contacted Microsoft and they told me I had to contact you to have this switched over to the 360. is this possible? the agent at Microsoft said that you have done this before for him when this happened to him. please help.