Let me clear it for you. First of all you are on a package that is no longer available. Till last month, I was also on the same package. Then Airtel introduced Rapid plans and I shifted to Rapid 2499 (16mbps till 200gb and then 512kbps). For Chennai there is one Rapid 2399 available I guess.
So, from 175gb I shifted to 200gb, however speed remained 8mbps coz 16mbps isn't available in my area.
Now yesterday, I came to know about broadband surprises and being always a high bandwidth user and an old user, I received 50gb topup. So as a result, now I have 250gb in total.
I do not think it is unfair as most of the people who have been offered 50gb have been high bandwidth users and old users (more dan 6-7 years).