Airtel decided to treat VoIP separate from Internet pack which is not a good news.If you would like help this cause, please drop a mail.
http://www.medianama.com/2014/12/223-net-neutrality-violation-airtel-introduces-differential-pricing-for-type-of-mobile-internet-usage/
You can use this email-template http://www.reddit.com/user/homelessvagrant