Airtel — Defamation suit

Address:

Hyderabad, Andhra Pradesh

I have my service provider as Airtel. I have taken a Postpaid SIM .Due to some unexpected problems i have not paid the mobile bill for a month.
The Airtel service providers traced the call to whom i was calling(Then service provider call to one of my friend saying that i have given his reference number to contact and asking him to pay the bill.).They called to somepeople who are not known to me also.

How far it is good to trace the number and calling the other people to pay the bill of mine.(Saying a lie that i have given their reference number as contact)?