I received a debt collection letter from IC System, but their phone number was disconnected. I looked them up on their website and called that phone number, which kept disconnecting me every time I called. I do not know what this debt is for and I can not get any information about it, since none of their phone numbers are valid. I suspect this is fraud, but since it refers to XXXX, I am concerned because someone recently hacked into my bank account and tried to run charges through XXXX. I have not charged anything through XXXX and do not have a XXXX account. Someone is using my identity without my permission and now I am getting collection letters. How do I stop this and make sure my credit is n't adversely affected?