Airtel — airtel postpaid -change of base plan without my consent

Address: Srinivasanagar, Banashankari 1st stage, 560085

Hi,

I am using Airtel postpaid from more than 15 years, recently i have noted that airtel has changed my base plan without my consent.
I was using base plan of Rs 199 from June 2018 but in the month of September 2018 it was changed to Rs 299 for myself and my wife number without my consent. When i called the customer care, he is telling that they have sent messages regarding it to my mobile, which i have not seen at all. and he mentioned that As per TRAI guideline the airtel company can change the base plan by sending SMS without taking my consent. Is it true, by sending the SMS the telecom company can change anyone's base plan.

How can someone do like this without taking consent from me change my base plan.

This is happening for second time with me.

I want refund for my amount ([protected], [protected]) and i want to change my plan to original Rs 199.

Regards,
Eshwar M