Wrong information provided by Airtel for corporate connection

We are from NEIGHBOURHOOD HYUNDAI. We have 16 corporate numbers of Airtel. Before 4 month when we took airtel connection, they gave us plan of rs.399 in which unlimited calling, 20 GB data and 100 sms daily. Now again and again sms charges available in our bill. If at the time of taking the plan, Airtel said us that no sms charges deducted ,now why we pay for that? Now their executives contineously call us that pay the pending amount otherwise we cut your connection. Kindly solve our issue urgently because this is not our fault.this is teh fault of airtel only. Our relationship number is-1364613461

NEIGHBOURHOOD MOTORS
THALTEJ, AHMEDABAD 380059, Gujarat
Email: ixxxxxo@neighbourhood.co