Didn't get my code

For help with the Microsoft Rewards program, you'll need to contact their customer support via their redemption page.

Hey there!



I sent you a message over Xbox
Live. Please check your inbox for further information!



Enjoy!

The code would have been sent via XBox Live messages rather than email and would've been sent around the 10th of October. Best bet might be to post over at Forza's forums (https://forums.forzamotorsport.net/)
or pick one up in the Auction House.

Phone and chat support don't handle promotions so they are known for giving incorrect information unfortunately.

Unfortunately support gave you incorrect information. Per the terms of the offer, a credit card was required. So since you used a prepaid code you would not be eligible.

Terms and conditions:

Valid only for new subscribers or users who canceled their subscription before 10/1/2018. Limit: 1 offer per account;
credit card required. Only valid through link in this offer, in all Xbox Game Pass markets excluding Quebec. After first month, subscription continues to be charged at the then-current regular
monthly price (subject to change), unless cancelled. Plus applicable taxes. Game catalog varies over time. Not valid for existing subscribers . After promotional period, subscription continues to be charged at the then-current regular monthly price (subject
to change), unless cancelled. Plus applicable taxes. Limit: 1 offer per account. Only valid through link in this offer, in all Xbox Live markets excluding Quebec.
Credit card required.