Unable to pay Credit Card amount.

Hi, My name is Gaurav, I have been customer to HDFC bank since 2007 using the banking and credit card. However, for the past three months I was facing financial problem , lost my job unable to pay credit card amount including min due and I am the sole owner at home who is taking the responsibility for wife and child. And the amount around 3 lakhs. Now, I am keep getting calls from collection team Or dept team. Keep telling me pay the amount I told them I have been good customer to the bank keep paying the amount for the last 10 years now I have some issue that is why unable to pay the amount. Now they are calling my father's cell phone and harassing him that they are sending the bikers and they will take the amount even they are not giving call to my cell phone. One day man and women came to my house around 8pm (29th july 2017) in the evening asking about money. I told them I dont have money to pay and I will contact HDFC bank (Gurgoan) and they will help me then she said they will not help I am the main head I will make the decision they are not. Then I told then please go its around 8.45pm then they left. Still she was keeping saying pay the min due Or else we have to take another action also, she was saying I can not got for settlement Or close the card which is incorrect. And the main thing which I was noticed she was keep asking about to pay min due does not giving any solution. Then I contact bank they told me they have not sent anyone. Tell me what to do?