Starting from Decemeber 1, 2011 MTS will withdraw the call balance SMS alert for Kolkata & West Bengal subscribers.
Currently MTS sends a balance notification SMS after you make a outgoing call. Being CDMA, MTS can not send the balance information over USSD like GSM player.
It is annoying to some users as it fills up the inbox specially those are with low-end handsets with limited SMS capacity. Not only this during this SMS delivery you can not make another outgoing call.
You can re-activate this service by sending 'START AOC' to 51230. You can check your balance anytime by calling *225# to get your balance details via SMS. You can also check balance by sending BAL to 155 or 51230.
The revert SMS includes all details of your prepaid account - main balance, promo balance, SMS balance & data balance.