Airtel — CHANGED MY SCHEME WITHOUT MY KNOWLEDGE

I am Sukesh T N , an old customer of Airtel Telcom.And i had an IRIS SIM ([protected]) which has been used by my Wife,and calls from the mentioned mob number to my personal number [protected] has been completely free.But from today onwards free service has been Deactivated.I had informed to customer care,but they are saying that your scheme has been changed to 50 ps/sec .I want complete explaination why you had changed my plan without informing me.So u had cheated the customer,thus you will definitly loose your coustomer. Please do reply,after that i will launch a complaint to INDIAN CONSUMER COMPLAINTS FORUM.