Hello members,I have been using BSNL unlimited Plan 1350 combo for 2 months now. Means, since January 2012 i have this plan till today. Now i want to apply and change my plan to Limited 250 Plan as i have a long duration during which i am not present at home. In plan 1350 BSNL gives 4 MBps speed for first 20 GBs/per month, thereafter we get 512 KBps for the rest of the month (everything is unlimited). So, i want to ask that if i apply for limited usage 250 plan today then what will BSNL do with the bill?? Means, i had completed 20 GBs for this month (March 2012) and now i want to apply for plan change. So, will BSNL charge me for those 20 GBs or will it take only the rental upto the date of change of plan (means today) according to existing 1350 plan????Please advise me whether i shall change the plan today or shall i wait for end of this month????Thanks.