Threats of Lawsuit..............

Received a call from Mr Wilson of this company at my home which he said that he did not know that. He did not tell me he was from a collection agency trying to collect a debt from an inactive non profit from 3 years ago. Told me that I was personally responsible because I set up the account. He gave me 4 hours to settle the account with some arrangement.  I told him that this non profit is not active & has no money, he did not care.  He said, "so you are refusing to pay" and I said I am not refusing anything but I need to look in to this.  He kept implying that I would be sued & am personally responsible for this debt, which I did not sign a personal guarantee, I was authorized to open accounts.  I have not been actively involved with this company for years and I feel like I am being exploited, threatened and harassed here.  LTD/Mr. Wilson have violated the FTC settlement.  How can this company still be in business?