Wrong bill

Location/place: Mumbai

Name of company/service: VODAFONE

Hi

I was using vodafone postpaid card , and after three months of usage , in the fourth month i have receive the bill of 10,600 . Where my credit limit was only 2,000. And the bill amount is high because internet plan which i have never activated , and people are troubling calling me everyday , and without checking they are forcing me to pay thr amount .