Got connection in Nov 06. first month itself I asked them to change to a different plan (fixed volume plan - 1.5 GB @ 512kbps) on the 25th of nov (they have a rule that request should be before month end.)plan didnt get updated on 1 Dec. Instead it got updated on Dec 12. Then they calculated pro-rata quota from 13 to 31.
e.g. quota for full month 1.5 gb = 1536 mb (daily quota of 49.54 mb)on 13 Dec, I was given 941 mb. till the 12th dec I had used only 250 mb, so I asked for the rest of my quota. i.e. (1536-350 mb) = 1186 mb.
So they informed me that it is based on their calculation. my question was , I informed on time, it cannot be my problem that they changed late. After that, since I am computer savvy, I started tracking my usage. on a particular day. (from midnight to midnight.), I wanted to test how they calculate volume. so I used a download url which I had got 2 days back (not an html page, but download url for file.) and downloaded the file. the file size was 180 mb. which got downloaded within the day. but after 2-3 days I saw their usage chart and it was showing 290 mb.
I wrote a mail to them and I got no answer. from january onwards my usage chart stopped getting updated.
For the next 6 months, I kept requesting the usage chart and I never got it. all mails were written to ALL their email ids. (billing, usage, other engineer ids, local coordinator id. etc)
Instead I started getting bills of more and more amounts. like my fixed amount was rs. 561, but I would get bill of 800 without any extra usage and if I asked for usage chart, my connction would be disconnected for 2-3 days and local and direct hathway people would give all vague answers.
Since I had no alternative (no other providers in the area. previously I had sify account, but sify provider ran away and rumours is that hathway is owned by some mp/mla and his people harassed the sify person by cutting cables etc. so he ran away.), I lived with this for almost a year since no other provider was there.
Finally there is an alternative provider which I have taken connectivity for last 2 months and again as usual hathway has not even sent bill and disconnected my connection. Previous bill hathway charge additional rs. 561 and when I called and asked I was told this is additional usage. (i stopped using hathway during night time as I have night time free plan from other provider and I am home only from 11 pm to 9 am and I dont use internet in the morning before leaving for office.)
Again I asked them for details of the bill and now I am told it is previous bill. After all this harassment I am not going to pay to hathway and am waiting for them to pull some stunt (once they had come and started insisting on my old father to pay the bill.) so that I can take them to court and it is most amazing that the government is letting these cheats get away by saying connection "upto" 512 kbps. I have never got this speed. there should be law that atleast 80 % of the time this speed is received by consumer
Apart from this there seems to be another scam of NOT answering calls for a long time so that bigger bill is got (in Mumbai atleast) ...maybe tata is sharing profits on call to customer care number...