Vodafone India — Activation of MI_C_V_155_30d_d1GB_MO_2G plan without my knowledge

Address:	700117
Website:	vodafone.in

I have no idea when this plan was activated in my postpaid connection. Its just for past few months that i noticed an unusual hike in the bills. I used to get bills around Rs 900. Presently they have shot up to as high as Rs 1800!! It is just this month that I scrutinised the bill to find that the plan has this extra thing activated without my knowledge and are chargig accordingly. I dont even use a smartphone for this number!! Yet I am paying hefty bills for a internet plan!!

Please help!