MTS / Sistema Shyam TeleServices [SSTL] — VAS is added again and again even after complaining multiple times

Address:

Chennai, Tamil Nadu, 600052

MTS is adding VAS without my consent and even if I cancel they are activating without my knowledge again. We use a data card for my family. Even after multiple complaints they are not acting on it . This is happening for the fourth time and even if I don't use and cancel also they are charging and reactivating. Some stringent actions should be taken and process should be changed when we add new VAS we should send mail or SMS to provider rather than simply activating by provider itself.