I have been using an Airtel 4G router which stopped working one week back. Ever since I have made daily calls to the Airtel customer care, visited their store four times, got the sim changed, but the fault has not been fixed and no engineer has been sent to check and rectify the fault. This has caused me a lot of frustration, loss of time and energy and disruption of work. It seems Airtel is sitting smug in their sense of monopoly because there are not many intercom players to give them competition. Its been a most disgusting and enraging experience.