HDFC Bank — hdfc credit card hidden charges

Address: Mumbai City, Maharashtra, 400059

Hello,

I was asked to take an hdfc credit card by their staff. The man kept saying "free hai madam... Lifetime free hai madam". I had specifically asked him if i would be charged anything in the future for it, and he said no. Absolutely no payment required. But i got a statement saying i've to pay around 1500 for some one assist thingy.
I went to the bank to inquire and those people apparently had no information about the credit cards. They said they only sell it, and for every other information i'll have to call up a number. These guys are just sitting there like salesmen and selling cards.
And most importantly.. The man who activated my card did not inform me that he is also activating this one assist programme, neither did he tell me that i'll be charged for it. And now i have to waste my money due to their efficiency.