In the last three years and including October of the current year, the Telecom Regulatory Authority of India (Trai) has received 80,494 complaints from subscribers, which include 20,659 against Bharti Airtel, 17,778 Vodafone, 12,760 RCom and 8,608 against Ideal Cellular.
This year, as of October, the regulator received 16,668 complaints. This includes 3,475 complaints against Vodafone, 5,661 Airtel, 2,907 Reliance Communications and 1,769 against Idea Cellular.
Sinha also informed Lok Sabha that Trai has imposed Rs 5.6 lakh penalty on seven operators -- the highest on Vodafone -- for unjustified rejection of mobile number portability requests in the last three years.
The regulator imposes financial disincentive of Rs 10,000 for each instance of MNP rule violation by operators.
Trai has penalised Loop -- it closed operations in November 2014 -- in 9 cases, RCom and Aircel in 5 cases each, Airtel 4, Idea and MTNL in 2 cases each, as per the data.