.
Okay, so it looks like the 48 pack is not just a data pack, but also doubles as a main pack.
In that case, I believe that your old data balance from the 98 pack should still be available for you to use, albeit later. You should still be able to use it, if you fully consume the 3GB from the 48 pack before 28 days.
Also, the 98 pack data balance should be carried over again, if you recharge on the last day of the 28 days outgoing validity.
This time, for example, if you recharge with Rs.45 on the last day of your current 28 day validity period, you should still be able use your old balance from the 98 pack for another 28 days.