Service control (activation, deactivation, status checking) can be performed by free USSD-request .
Voice menu. Make a call to the short number 9977 from your phone. Mobile answering machine will play the messages left to you, and specially selected system of voice tips in the setting process and usage will help you to set service in the way you need. Listen to the instructions and press corresponding buttons at the telephone. Just listen to the instructions and press the corresponding button on the phone.
The service is free.