Hi. Our domain is hearingc.com
The webhosting is under godaddy
its managed by a third company and they are refusing to share the username on file or the PIN number
my boss doesn't have the details not even the email ID is available
now to do on page seo we need the details to make changes
how do I retrieve it
If they refuse to give the website details so what you can do is tell them to do the changes. As I'm also an SEO Expert I understand these so my advice is either you take complete control of the website by transferring to your account or give the required changes details to them and ask him to do it for you.
Of course he will demand some amount of money but that's the only way.