Can I sue a credit card company for harrassing me because my identity was stolen?

2 years ago a "friend" took out a credit card without my knowledge or consent. It had a 5000.00 limit, he wrote bad checks to charge more and ran it up to 14000.00 before I found out what was going on. He took responsibility for it and set up a payment plan to pay it off. I was told by Citibank that It was cleared up. Now he stopped paying and they are back to harrassing me again, even threatening legal action against me. This has been very stressful and is putting a hugh strain on me and my family. Also, I told them I would press charges if the sent me the info like copies of signed cc slips, IP addresses of the computer used for these transactions and so forth. They will do nothing.
Thank you,
Fred Montgomery