Airtel — without confirming upgrade postpaid plan 649 to 799

Address:

Chennai, Tamil Nadu, 600075

Just opened notifications and airtel upgraded my plan from 649 to 799. Called 121 immediately and she denied helping even wen it was still under process on 6th dec. Same night my internet was disabled. When enquired told me tower under repair and will take 4 days. Then how is my other prepaid sim working fine. Please help