Airtel looting the customers by activating vas without customer consent

Hi, I am using both prepaid and post paid connections from airtel. In pre paid connection, many value added services are activated without my consent and everyday rs.10 or rs.20 are getting deducted every month. I tried to reach the customer care, but I am not able to get through the pre recorded answering machine option and speak to customer care. If I call from my post paid connection, they disconnect the call saying "this is post paid department, we do not handle prepaid queries". How we get to speak to customer executive and resolve our queries. The customer care number - 121 is of no use, only pre recorded messages are being played. And there is no option to contact customer executive. Even if I stop the services, again in next month, new services are activated without my consent. It is not on 1 connection. It happens on every airtel connection. We have 3 airtel pre paid connections in our family and on call services are activated without our knowledge or consent. This is highly unacceptable. Why do airtel always active the services without customer consent? is there any way to stop this from happening? why are they looting the customers without their knowledge? mobile number on which these services are activated are 1. 1027 2. 6110