Citibank — credit card closed account not updated in cibil

We have been citi bank credit card holders for a long period .we closed the account in the year 2014.as a settlement .But now we understand that it is showing as a negative account and reflecting a lower score on card holders cibil report.we tried to contact citi bank helpline numbers but not getting connected to the right department.pl guide us as to to how to go about in resolving the issue.