Game pas ultimate

Hi,

Friends of mine said that if you take the Game pass ultimate deal for 1€, that this will upgrade your Gold subsription for the remaining time for just 1€ and just turn autorenewal off.

So I did a quick search on the xbox forum and there it says that your current xbox live gold will be upgraded to Ultimate for a maximum of 36 months.

Sweet deal I thought, so I bought 36 months of Gold because my Gold subscription was about to expire anyway.

So when I choose this option on mine xbox, it says that they will bill me 1€ for 1 month and for the other months 12.99€ and it asks me to give my creditcard data...

My question is, how does it actually work when I grab Ultimate? Is it actually 1€ for mine remaining 36 months and after that, it will ask me for the 12.99€/month? Or is it just 1€ for the first month and the rest of my subscription 12.99€/month.

I'm confused....

Thanks in advance!

:)