Trai — minimum recharge every month for using incoming and outgoing services

Telecom companies such as Vodafone and Airtel have stopped the incoming and outgoing services despite having a lifetime validity sim card with a certain amount of balance in prepaid sim. As it being my old number I have connected it to all major services such as banking, income tax, and for various other private institutions. I am having problem to do my day to day important activities related to it. It is highly ethically incorrect just to increase the profits. If they are not able to sustain they should not run the company rather than harrasing it's customers.