HDFC Bank — collection agent threatening

Sir i am subhas chandra deb hdfc cc holder a senior citizen customer.. I agree for settlement of my card but due to my poor financial problem i am unable to pay settlement installment on time. I spoke to collection agent and hdfc collection manager also about the matter as i am a pension holder not getting sufficient pension to pay that amount as i am not able to running my family expense also. My daughter is doing a job we are totally dependent on her. Collection agent uttam das, fe i'd no utda100169 agency code kel agency name e solve solutions ph no [protected] threatning my wife and daughter. He threatning and telling that "i will force your daughter to get resign from her job if you not paid.. I will contact local club that she will not able to go office"in hindi "main use office jake uska naukri kha jayunga usko chorenge nehi".. And he will doing rude behaviour with my wife when i am not in my house.. He threatening to my wife saying"i wl come your home with lots of people" qnd shouting very badly.. Now my wife is getting ill for this behaviour.. Kindly guide what i have to do for this.. I request you to please do somthing so that my daughter and wife stay alive. I will write same thing to rbi and hdfc bank also...
Kindly help.. I am not able to pay high amount as my financial condition is very bad