Last I heard is hdfc only offers cards upto regalia (not even regalia gold in most cases) as LTF. But your best bet is to mail the grievance team and find out if you can convert regalia gold as LTF based on your relationship value with HDFC or ask your imperia RM to help if he can do something. Tell them you are ready to even close/downgrade the card if required to get a LTF card.