Who is an expert in dealing with HMRC on the phone?

I lost my previous number and can’t access my HMRC account. I want to change my phone number, but I’m facing issues when calling them.

They ask a lot of security questions, but there are always problems, like my details not matching.

Is there anyone here who has expertise in dealing with HMRC?

Thank you for assistance.

You should be the one dealing with HMRC, and you don’t need experts to speak with them. If they say that the details don’t match, then you might be providing something incorrect. Did you try calling them?