Discover Credit Card Complaint

Discover Credit card department,

Credit card protection / Debt protection Illinois

on - i enrolled in - to check my credit.And on that date i found a credit card that was not mine, but on my account.So i called - and asked them what this discover credit card is doing in my account.They told me that there was a discover card issued to a - using my social security number on - at the address of - Il. -.That was my sisters address which she had used my social security number to get this credit card.She did it in the past to me - other times.Plus she even got a - Il . -.I called discover and gave them the credit card number of -.They in turn did not investigate on that they investigated on my legal - i have that i did not even use.The discover card that my sister got is still in use.My sisters name is -, but she goes by her maiden name of -.I want discover to close this account and investigate, but they will not.They said - must be wrong.- told me they are not wrong that is the information given to them by discover.I have copies from - showing this.I send discover all the information and my identity, but they still refuse to do anything.Please help me out because i want to have my sister arrested for this so she stops.