fraud in billing

Location/place: mumbai

Name of company/service: vodafone

I have purchansed a tab and vodafone agent has offered me data plan.
After two month of usgaes i selected my plan of 1GB rs 250. After month usages company bill goes to rs 2000. Company has not informed me about my usgae and not even sent me bill and asking me to pay bill.even company has stopped my other no which i was using from last 12 years. Many times i visited their center , sent mail and called their call center but company is not ready to accept their fault.