MTNL has two systems, accounting and technical. The technical dept tracks the usage and gives it 'manually' to the accounting department. So when you activate a plan and its updated only in technical and NOT accounting, these kind of problems may occur. Note the rental that is being charged for you. If its 849 then you can easily show that as proof that your account is supposed to be activated. I've heard case about a guy having similar problems. If it comes as a consolation, he did get his refund back, not just once but in two consecutive months !