HTML headings in the contact form return mail

I am trying to add HTML headings in the contact form to be displayed in the posted mail, using the Custom HTML
PERSONAL DETAILS
Full name: *
Date of Birth: *
MEDICAL AID DETAILS
Provider: *
BANKING DETAILS
Account Holder: *

The mail received does not have the headings for the different parts of the form info but only returns:
Full name:
Date of Birth:

Provider:

Account Holder:

How do I let the mail displays the info PERSONAL DETAILS, MEDICAL AID DETAILS etc?

Cheers,
Schalk