Wrong name on 15 year Sons form for National Insurance Card

Hi, I received a HM Revenue & Customs National Insrance Number form for my 15 year old son. The name on the form is totally incorrect. My son was adopted at the age of 3 years. For some reason the form contains his birth name and not his known adopted name that he has been using for the last 12 years. I spoke to a representative at the national insurance contributions who told me my 15 year old son needs to call them, they can't discuss it with me his mother. It was pointed out this is not our mistake it is yours only to be told the same thing again. They couldn't help, The representative didn't even ask for the incorrect name. This has caused distress to my son and family to take him back to a situation that was and can be stressful for him through no fault of his own. Please can someone contact me for this error to be corrected.

Hi,
I apologise for any distress this may have caused, please call us on 0300 200 3500 to amend this.
Your son can come to the phone and update the details held on his record, if comfortable, or yourself (with prior consent from your son) can talk on his behalf and we can submit a referral.
As a result of the referral, you will either receive the National Insurance Number with the correct details on, or receive a form to complete if further information is required’ 
Thank you.