Standard Chartered Credit Card — abusive words by the bank staff

Standard chartered added some life isurance produts on my card without my consent & when i refused to pay the amount , every fortnightly they are calling me on my nos. with threating & abusive words.Till date no bank official staff has visited me with the official leter of amount due & the reasons of being the products attached in my card. Some imediate leagal help is solicitated in this regard.