Airtel — airtel 799 family plan

Address:	Chennai, Tamil Nadu, 600020
Website:	airtel.com

While discussing the airtel post paid 799 family plan the sales guy had mentioned it’s a 60 gb data every month and the left out data will be carry forwarded unconditionally. I got accumulated till 351 gb and all of a sudden a 100 gb data is vanished and now it’s only 260 gb left. When i called the customer service person he gave very wague response and i felt it’s a data theft by airtel. My issue is not been resolved for more than 3 months.