SBI — collection agents unethical and unlawful behaviour

Dear sir / madam,

I am sbi credit card user from last few years, i made all the payments on time but due to some medical issues in my family i am suffering from financial crises and this situation i already informed to the bank. But from few days your collection agents are misbehaving with my wife & relatives, they are threatning them, and doing abusive & irritatiing messaging to my wife's mobile. I am not able to sleep now, i am feeling very much regret now, why i have opt sbi card. I request for action against that person.

Thanks & regards
Deepak