Your DH should email Membercare asking why the account was disabled. Often, they just want proof that he is a real, live person and not one person doing many accounts. They may ask for a copy of his driver's license or other ID to be faxed to them. Once they have the information they're looking for, the account will be restored with all points still in his account.
]edited to add:
Here are the phone numbers that I have for MyPoints:
1-888-262-4528 and ask for Membercare
FAX - 1-888-333-6260