BSNL/ev-Do Datacard Internet Provider — very poor services and excess rate charged

I am using this data card for last 10 months . Initially they assured me that their services will improve within one months and it will work in every major cities in India .But sorry to inform you this data card is not working outside the Guwahati city and its network is so slow that sometimes it takes 2 to 3 hours time for internet connection and the peed is so slow it takes hours for openig awebsite. It is hardly possible to watch video through this connection. When I had taken the connection BSNL charged 250 plus service tax but now they are billing 600 plus service charge. How the BSNL has increased the exoribitant rate without informing the consumer for no additional services. So there fore I request you to refund my excess billing and increase the speed and networking area.
Regards
SUSHIL SINGHI