I have experienced the same with Tata VSNL broadband in Chennai.

I have more other experiences, i tried a lot to record, write, save mail, and talk out the customer service executive; but all went in vain. All was leading to nowhere.
I went to complaint the same to their head office in Chennai, had to wait for almost 1 hour to meet some dickhead, and get nothing constructive out of it.
I was not able to do proper business and I had once run all over Chennai roads to find a cyber cafe in the middle of the night at 3AM to submit a project in time, else would loose 1000s of dollars and a big project, thanks to the great service of Tata Indicom VSNL broadband internet connection.[they claim 0% downtime!]
Calling the customer support is a nightmare:
1. They do not have a toll-free customer care number.
2. Moreover the calls are STD calls taht landup in Hyderabad.
3. The people in Hyderabad do not understand the local locations and do not know addresses or names that we pronounce. Hence so many practical problems.
4. CC executives want to greet and put the phone down, they do not try to understand our problem, they abruptly cut my call during conversation.
Overall it was a nightmare to be a customer with Tata Indicom broadband. I had prepaid for 6 months, so I could not do anything else other than watch them take me for a ride and puncture my feelings and day today activities!
I would do anything to wage the war up against their ass, and bring justice to fellows who have the same problem, we all have opted for Tata Indicom only on the basis that they are the monopoly provider in our area. All the best and all the good luck to Lal.