I faced the same problem while switching to the 'Superblast 30 GB' for ₹1250 [Monthly, Postpaid], at least I'm getting 5 GB more than the previous plan [HD Stream 3]. Also, no renewal issues on this one. They send a monthly bill, but the connection continues to function unlike the prepaid plans which get disconnected on the mentioned date.
This. Once you get used to speeds like this even 5 Mbps feels like a snails pace. I've seen that you can easily go beyond 2 GB in a few hours if you don't watch what you're downloading. A workaround I've been using is changing the adapter speed to '10 Mbps Full Duplex', when you need the full 50 Mbps speed just change it back to 'Auto Negotiation'. That way at least you wont burn up data on YouTube videos, which you might not like, but has been buffered completely.
Edit: I wonder if they'll come up with some 100 Mbps plans with reasonable download caps by the end of this year.