HDFC Bank Credit Card — abusive behaviour of collection manager

I am using HDFC Bank Credit Card, since quite some now, due to my frequent travel in remote areas i did not had network facility so that i can initiate my bill. which is due this month (small amount of 3000/-)
collection agent was sent to my elderly parents home, and he misbehaved with them, when they called me the snatched the phone and threaten me on the mobile.
later on a collection manager by the name Sajal Paul ([protected]) misbehaved and became abusive.
Is this how HDFC employees are trained?
we are not compulsive defaulters and there should be standard and decorum while talking to clients.