@sankalpit: im guessing the JTO is confused and ended up misinforming you
Point duly noted. A BSNL JTO's ability to become confused and spread confusion is never to be underestimated. However, he was quite convinced and confident. Besides, there's this notification on data.bsnl.in portal about name change for existing plans, so we just have to wait for a more official announcement which will settle the finer details.
lawsuits will flow like wine then...
Crucially, BSNLs T&C do not mention about BSNL reserving the right to change plans whenever they see fit. However, we also know they are a sarkari operation, so the court will side with them and interpret that it is 'understood' that BSNL reserves all rights other than those explicitly granted while signing for service. And sadly, BSNL never promised that it will not change or discontinue its existing plans in future.
I don't think we should worry about this month. BSNL moves quite slowly (as we all know), so it will take them some days before the new plans and usage policy is announced. Next month will be tricky, they will either change plans midway during billing cycle (god help us) or wait for the end of billing cycle and force the migration on undecided users from Novermber. Let's see.