Airtel — postpaid plan change

Address:

Ajmer, Rajasthan, 305001

I have been using airtel postpaid for about 2 years now and my plan was my family plan with rs 199 per year for a family member and now they have changed it to rs 99 per month without notifying me about it or taking any confirmation from me or communicating me.
When i call them they just give some stupid answer and neither anyone is helping at their offline store.
My main number is [protected].
Shubham sharma
[protected]@gmail.com