Airtel
Unwanted calls from Airtel collection department

I am getting frequently calls from Airtel collection departments for asking "Unknown person". However, After asking the reason for a call they tell me that person (Unkown name) has given a ulternate number.

I had a compaine in Airtel Gallery about same but I am getting call from Airtel.

I am vodafone customer.

There are few no from where I get call are mention below: -

02041003421

02267840500

02041003410

From Last 5 months I am getting call in between office meeting and work place.

Please guide me to handle from such situation.