Any person who falls under the category of 'consumer' under Section 2 of the Consumer Protection Act can file a complaint. Sections 2 and 12 read together provide that the following classes of people can file a consumer complaint: 

(a) a consumer; or 

(b) any voluntary consumer association registered under the Companies Act, 1956 or under any other law for the time being in force, or

(c) the Central Government or any State Government, 

(d) one or more consumers, where there are numerious consumers having the same interest. 

It was decided in the case of Motibai Dalvi Hospital v. M.I. Govilkar [1992 (1) CPR 408] that where a complaint was initiated by a person, it could be taken forward by his / her relative or friend. 

Hence, even a friend can continue a consumer complaint, once initiated by the consumer under Section 2 of the Consumer Protection Act.

You can now prepare your consumer complaint against a product or service at http://www.vakilsearch.com/consumer-protection.

You could also file consumer complaint against Airtel, Aircel, Vodafone, Tata Docomo, Idea, Reliance.