[Resolved]  Idea Cellular — huge difference between postpaid bills and prepaid plan

I use idea post paid connection with monthly rental plan of rs.349 and i get unlimited calls both incoming and outgoing, daily 100 sms and but only 1gb data for the month while the same company provides 1gb data in prepaid plan.
Also i get extra amount charged in the name of gst with18% rate on my bill. Why such a huge difference between post paid bills and prepaid plan if there is one country one tax?
Is this government sleeping while all these is going on.
Both government and companies are looting public.