Plus, BY LAW, they MUST provide a debt validation letter proving that your wife owes the debt and that they have the right to collect.  So if he blew you off about not having to provide validation, then he is a scammer!  Also, as you said, your wife settled this debt in 2009, so you know he's blowing smoke.  You can report them to the FTC and your state's Attorney General, and also send them a cease and desist letter via certified mail (return receipt, signature required).  They may still call, but you can safely ignore.

The Federal Trade Commission (FTC), the nation's consumer protection agency, is warning consumers to be on the alert for scam artists posing as debt collectors. It may be hard to tell the difference between a legitimate debt collector and a fake one. Sometimes a fake collector may even have some of your personal information, like a bank account number. A caller may be a fake debt collector if he:

?is seeking payment on a debt for a loan you do not recognize;
?refuses to give you a mailing address or phone number;
?asks you for personal financial or sensitive information; or
?exerts high pressure to try to scare you into paying, such as threatening to have you arrested or to report you to a law enforcement agency.

If you think that a caller may be a fake debt collector:

?Ask the caller for his name, company, street address, and telephone number. Tell the caller that you refuse to discuss any debt until you get a written "validation notice." The notice must include the amount of the debt, the name of the creditor you owe, and your rights under the federal Fair Debt Collection Practices Act.
If a caller refuses to give you all of this information, do not pay! Paying a fake debt collector will not always make them go away. They may make up another debt to try to get more money from you.?Stop speaking with the caller. If you have the caller's address, send a letter demanding that the caller stop contacting you, and keep a copy for your files. By law, real debt collectors must stop calling you if you ask them to in writing.
?Do not give the caller personal financial or other sensitive information. Never give out or confirm personal financial or other sensitive information like your bank account, credit card, or Social Security number unless you know whom you're dealing with. Scam artists, like fake debt collectors, can use your information to commit identity theft ? charging your existing credit cards, opening new credit card, checking, or savings accounts, writing fraudulent checks, or taking out loans in your name.
?Contact your creditor. If the debt is legitimate ? but you think the collector may not be ? contact your creditor about the calls. Share the information you have about the suspicious calls and find out who, if anyone, the creditor has authorized to collect the debt.
?Report the call. Contact the FTC and your state Attorney General's office with information about suspicious callers. Many states have their own debt collection laws in addition to the federal FDCPA. Your Attorney General's office can help you determine your rights under your state's law.

http://www.consumer.ftc.gov/articles/0258-fake-debt-collectors

Harassed me and my parents who live in NC about a balance my wife had from an old credit card that she settled back in 2009.  Spoke with a couple different employees.  Each one claimed that we owed a different amount than another.  When we asked for documentation regarding the account, the manager said they have up to six months before they have to provide any documentation, but that they would sue my wife before that time period was up.  When my wife starting asking questions about the validity of the company and their claim, the manager got extremely defensive, made threats about how this would affect her career, and hung up on her twice, only proving their lack of professionalism.  If they call you saying you owe money, call the company they claim to be representing first before giving them any info or money!