Trai — need a proper explanation about call cost and data cost in airtel, vodafone, idea, aircel and other nws

Hi, myself nishanth using aircel simcard, before 8 months the cost of 1gb data was 200 to 300rs, but now they can provide unlimited calls with daily 1gb data for 350rs, how it is possible, now they can provide this much means previously we are cheated by telecommunication corporate for more years, we lost more money due to this, need a proper explanation are else ready to book a complaint against all telecommunication companies