[Resolved]  Airtel Postpaid — billing through ECS

i have taken a post paid connection of airtel in the all india plan with the facility of ECS for my post paid bills to be debitted from my bank account every 15th of each month ..yet the customer care has sent me sms'es stating termination of connection if credit limit is not paid. if all of the terms and conditions for payment of bills have been fulfilled then the monthly bill incl the credit limit or its excess should be deducted from my acct on the prescribed date without disconnecting my number. please explainthe actions of your billing section.