Unable to redeem code for Game Pass Ultimate from Tim Hortons Roll up The Rim

I was given a Game Pass Ultimate code from the Tim Hortons Roll up the rim event, and I get a message saying "Check the instructions that came with your code. You might need to redeem it on a different web page." This message shows up whether I redeem online through my account settings, or from my Xbox Microsoft store, or click the link in the email from Tim Hortons. I contacted Microsoft, they said to ask Tim Hortons for a new code. I asked, was told that they receive their codes from Xbox and to contact them... So now I'm running in circles here. I currently have a 3 month subscription to Game Pass Ultimate that will be ending mid May 2021. I'm hoping to have this sorted out before I get charged for another month... Has this happened to anyone else?

:)