Unable to properly change region

Try https://www.xbox.com/sr-Latn-RS/redeem or http://microsoft.com/redeem

You can change the region of the site in the far bottom left corner of the site.

Again, I meet the criteria on the support page. I have never changed region before.

Sorry to hear it. Please check the link below for reasons why you may not be able to change your region.

support.xbox.com/.../change-region

If you can't find a solution there then I would recommend contacting phone support for more assistance.

Phone: 800 142 365 (landline) or 239 000 459 (mobile phones)

You have e to do it at account.xbox.com

You must usr a payment method from your region as backup

Using the regiom migration tool can only be done every 3months

If your account is less then 3 months old you must wait for the 3month mark

If you bought a code from another region that would be why you don't buy out of region codes

Sorry but no one here is going to be able to help with this. Support sends people to the forums when they don't know an answer or don't want to do the work related to it.

In order to solve this issue someone would need to have full access to your account. No one on these forums has that kind of access nor should they try to get it. Your best chance of solving this issue or getting help would be by contacting phone support
again. If the person you're speaking with cannot help then tell them you want to escalate the issue for better assistance.