Forza Horizon 3 Warthog Code not found?

Ages ago before even purchasing Forza Horizon 3 I received a code giving me a warthog for the game Forza Horizon 3. Now a year ish later I know own the game I've gone back through my messages with Xbox Live to find that that message is no where to be found.
Do these messages delete themselves after a while or...? Any help finding a way to getting my code back would be fantastic. Thanks.

:)

 

haven't receive forza horizon 3 Warthog code

Ich habe halo 5 guardians gespielt und keinen code für den halo warthog in forza horizon 3 bekommen

[Translation]

I halo 5 guardians played and not get a code for the halo warthog in forza horizon 3

 

Redeeming a code for the Warthog on Forza Horizon 3

I was sent here by Microsoft support about getting a code for the warthog on Forza horizon 3

I have installed Halo: Guardians and I have not received my WartHog code for Forza Horizon 3.

 

Hey there,

Unfortunately all Warthog codes that were sent out have since expired, and we are unable to replace or provide new codes over the forums. You may receive a Warthog directly in-game within the 'Gifts' menu once you unlock the Festival, but we are unable guarantee
if the car will be there.

Hope this helps clear up the concern.