I changed my plan today to 256 unlimited 999/-. But MTNL says this will be effective from next billing cycle i.e. next month. Strange ways of MTNL????????
I don't think that is right. I call and ask for a change and they change it within 24 hours and call back to confirm it once it is done.
This is possible at any time of the month and they'll charge you pro-rata rent and compute usage for the days under each plan.
I have never done it for the unlimited plan so I can't 100% vouch for it though but it must be the same principle thoughout.
Perhaps when they said it will be effective from next billing cycle, what they meant was that you see it reflected only in your next bill.
As Amish says, check your View Services page. But first wait for them to call and confirm. If they don't do that in 48 hours ring up again and tell them you docket number and ask for the status. Hope you noted the docket number.