Game Pass Ultimate Issue

Hello Forums,

So I recently converted my Xbox Live Gold time over to Ultimate. I am fine with this and is what I wanted to do. It stated wouldn't be billed till 09/14/2021 yet I was billed from the existing Microsoft wallet in the amount of 16.46. When I go to manage subscriptions it still states won't be billed till 09/14/2021. Just wondering why it converted my time till 09/14/2021 and then billed me the 16.46 (which is 14.99 + tax for me).

Thanks.

:)