I am availing HSBC Gold Credit Card, though I am not using it but I am getting calls from Delhi Office from Credit Card dept. of HSBC on frequent basis on my office landline, when I tried to register myself in DND list, particular link is not opening

For last few weeks I am getting calls around 3 times in a day, that is harassment, because when I am sitting in the office

I want to file a sue against HSBC Credit Card, pls. guide me the way forward

Moreover, I would like to add one comment for not using my HSBC Credit Card,

Approx. a year ago, I was ocassionally using HSBC Credit Card, on the basis of usage, I accumulated certain points for which I claimed for redemption, and the same has been agreed by their customer care executive but till the date after completion more than six months I have not received gift which I have claimed for, in short this Bank is cheater