speed still 2mbps here.
OK my service page is fixed and it shows that i am having unlimited plan. so it means i can download, but speed is still 2Mbps
should i start downloading or wait till next month O_O ???
If your service page shows your new plan and they have confirmed it by calling you, then you should be fine. My only word of caution for those who change MTNL plans is this. On the day of the change you can't be sure. So for that day only, assume the lower usage plan is in operation.
From the next day onwards you should be fine.
They charge on pro-rata basis but you cannot be sure which plan they will have in operation on the day when the change occurs. I also suggest that you print out the session usage details at the end of the month when you did the change and make your own calculation and compare with the MTNL bill.