charges deliquent on joint account, other person was in prison

Hi,I noticed that the last time I checked my credit report there was some errors. I had an account that I never used and there were charges on it and it was deliquent, it was a joint account, but the other person was in prison during the time of the charge. I filed a dispute online through the credit reporting agencie, but they seemed to just disregard it. I also called the company about the account and didn't really get anywhere. What can I do? Also there was addresses listed on my credit report that were wrong, could this be a sign of fraud?
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when you say never used this line of new credit card credit but it was deliquent
it sounds like you opened it up with that guy in prison
if you didnt do that
or dont know this person
then yes that would be a sign of stolen identity or fraud

if you disputed and it, it wasnt yours, and you never signed anything with this person, and it did not fall off
THEN
use the results from your credit dispute to follow up with the creditor and call the state attorney general if needed after you use this free debt validation form