So exactly what law are you referring to that specifies when debt is "too old to legally collect"? Because I know of no such law. I do know that there is a law called the statute of limitations which prevents them from suing you, but does nothing about telling them that they have to stop collecting, with the exception of Wisconsin and Mississippi where collection activity must also cease.
It really depends on who answers the phone on what name you will get. Some say CR&Associates, others Miller, Stark, Klein & Associates. They call from the number listed above and also 817-885-5039, or maybe another number with your home city area code. The Miller, Stark people are at least polite, wrong, all wrong on the law, but polite. The CR people just talk fast over you and say they are sending someone to serve you papers to sue you and this cannot be discharged by Bankruptcy, or SOL from your state. When you try to get information from them regarding proof of debt they hang up, they refuse to give you their address too. These are the same people who the FTC came down on for trying to collect on bogus payday loans in 2010. Laughing at them really pisses them off and kind of made my afternoon.
Add North Carolina to your list of Wisconsin & Mississippi. There are alos multiple States that require consumer disclosures when colecting on time barred debts that basically say.......this debt is too old and we can not sek legal action against you for paying, but if you do make a payment it could reset the statute of limitations. (CA, NM, NY, MA)