Hey Rakiim,
Sorry to hear that your purchase was made on the wrong account.
We’re not aware of any widespread issue with this, and this kind of confusion does happen from time to time. Considering that a new game / game version is launching soon, we’re bound to see more players do this than usual.
That being said, if you purchase the wrong game, or purchase a game on the wrong account, you will need to request a refund for this: we’re unable to change the license for a game, or move it from one account to another.
https://us.support.blizzard.com/en/help/product/services/334/1997/solution
Please make sure that the site doesn’t redirect you to another region automatically when creating the ticket (you can see the us.battle.net in the URL).
Also note that while there should be no issue in refunding this purchase if it hasn’t been used yet, it will generally take a few days / a week for us to process the request, and for your bank to transfer the money. This means that if time is important to you, and if you’re looking to access the Name Reservation period, it may be best to purchase the game again on the correct account, while waiting for the refund on the US account.
Hope this helps. 