Airtel - Abusive customer care

This is in regard to the Airtel digital tv connection that I recently had with Airtel. I had to remove it because the Airtel connections at my new place were weak. Airtel technicians themselves told that they can't resolve it. I had to go for another option. Despite knowing this, the customer care calls me up every fortnight asking why I haven't done any recharge. I repeatedly tell them that airtel connectivity in this area isn’t good and I have to go for another option. Today I got a similar call from another guy and he started hurling abuses and using foul language when I told him that I don't want any airtel connection. I have details of the guy who called. He said he is from Tilak Nagar, Delhi. He called up from landline - ****-*******
His mobile no. - **********.