ICICI credit card wrong bill

1.CC issued to me about 4 Yrs back.

2.In Dec 2006 i closed a CC

3.In June 2006 i got a first bill saying you have used 30 thousand

4.I lodged a complaint over phone .

5.Next month July they sent the Bill with ADDon card which i nevr used till date.

6.ICICI bank stated sending Gundas to harass and gt the amount paid from February 2008

7.Kindly let me know how to go ahead and resolve this issuee