HDFC has a dedicated Imperia Services Customer Care.
Their toll free number 18001023310 deals exclusively with the Imperia Banking, Infinia Credit Card and Diners Club Black Credit Cards. 1800118887 is the conceirge number.
Except the fact that U get to connect directly with the Customer Care people without waiting in a queue, there is nothing special in thr Imperia Banking Hotline.
Similalry their conceirge number is also offering very basic services, moat of which u can get urself on thr Smartbuy Portal. For everything else they simply keep referring to Smartbuy only.
Nothing beats the AMEX Platinum Conceirge in thr world. Ask for anything they do it for you.