I would like to request a refundfor purchases withoutmy consent

The best place to go for a refund would be here http://support.xbox.com/en-US/contact-us to contact account support (Not Ambassador support).

They will be able to look into this for you.

You can also check your Order History at account.microsoft.com under Payments & Billing tab at the top. From there, you can find the order in question and verify the ammount paid and method. Then underneath that order should be a link to "Get order help".
That will take you to a page that has further details on contacting the billing department and what can be done about the order.

For billing issues contact xbox support: (800) 469-9269 if you're in the US/Canada or
http://support.xbox.com/contact-us

Hey guys

My son had purchased 450k worth of vc on nba 2k23 without my consent. I requested a refund for this matter but it was denied without any reasoning? I was wondering if I could still received my funds back into my account as this is ridiculous due to the fact my son had bought it without my consent or me even knowing until after the purchase had been made and popping up as a notification on my phone.

Thanks

Did you son spend any of the 450k VC at all? If he spent even a little bit of it then that would be one reason they would deny a refund and they likely won't change their decision if any of it was spent at all.

I've seen that help page, but the games launch without ever showing a consent request/dialog like that.