could you help me?

Hello Andu, this is Manuela!. I'm an Independent Advisor and community user like you ready to assist with this.
Not a Microsoft employee.

I'm sorry to hear you're not able to create a new gamertag for your Microsoft account.
May I know which platform are you using to do this?
And, may I know what procedures you tried to fix this?

You'll need to contact support and speak to billing. http://support.xbox.com/contact-us

You would have to try contacting support and speak to billing. 1-800-4my-xbox if you're in the US/Canada or http://support.xbox.com/contact-us

Tried numerous times now keep getting spun in a circle by the bot on web chat and I have no idea how to sort this out so can stop it from occurring again. Could you please check on your end, i tried to purchase Xbox game pass ultimate. Said there was a problem on your end try again later. I did, it did not work. serval times after that. Eventually it did. but the times it did not was charged to my contract sim card (Three) and these charges occurred on my monthly bill. I'm sure I am able to send a copy of my bill via email if needed.

It's a known issue at the moment https://support.xbox.com/en-US/xbox-live-status?xr=shellnav