Vijian - I was in a similar situation last year having not used my Hilton card whereby the gold status was lost.
Needed to start using Hilton, so a swift call to Centurion, who called Hilton and a few days later, a gold Hilton card was issued with a new account number.
Apparently, at the time, it was Hilton's fault for not recognising the auto-gold-renewal aspect of the Amex-Hilton relationship.