you have to be sure that your credit card company is posting the same info to Experian, Equifax, TransUnion if you want to improve your credit score you need to dispute information that does not belong to you with credit bureau.
Here is the address,
Equifax Information Services, LLC
P.O. Box 740256
Atlanta,GA 30374-0256
1-800-685-11-11
www.Equifax.com
TransUnion Customer Relations
P.O. Box 1000
Chester, PA 19022
1-800-888-42-13
Experian
P.O. Box 2104
Allen, TX 75013-2104
1-888-397-3742