I have been using BSNL from past 8 year and in the initial days, it was hell. Lot of downtime etc, but from the past few years, its been very awesome. I am currently using the 1800 plan which gives you 100 GB with 4mbps in bangalore. Just to give you the uptime they provide, I had kept a heavy download of 78 gb and it was done in 2 and hlaf days non-stop! Not even a single time, the speed got reduced. I was so happy, I had tried 20 gb before but this is the first time using 78 gb and so happy that I am writing the review for the same:)
Regarding the customer service, yes, I agree they suck. I had faced many issues before and I all did was escalate it to the nearest manager of exchange and they used to fix it pretty soon. Apart from that, the bills are never wrong, no automatic adjustment, etc.
I highly recommend BSNL for everyone, since they have changed in a couple of years, I suggest you to try once. I feel sad for all the other reviews. I never faced such issues before.
Good job BSNL!