Goverment gateway still says NI doesnt match name

I changed my name earlier this year, i changed it with NI and had all the restrictions removed and double checked with HMRC that my NI matches my current name. i am trying to verify my identity for Goverment Gateway to apply for a UTR number, every time i put my NI number in with my current name im told my identity doesnt match, yet when i put my dead name its a match. i have no ID with my dead name attached and only have everything in my current name. What do I do? how do i access Goverment Gateway and verify my identity?

Hi,
Please contact our online services helpdesk to discuss 
The number is 0300 200 3600 and lines are open Monday to Friday 8.00am to 6.00pm.
Thank you.