If they are refusing to send you paperwork, that is a HUGE red flag that this is likely a bottom-feeding collection agency. I would tell them to send you something in writing. I also wouldn\'t give them any information until they do.
IF they send you a letter of collection, then you can respond by requestiong proper validation of the debt. This sounds way fishy to me. Plus, if the account\'s in collection, he already has bad credit and this will be on his report for 7 years whether you pay it or not.
How to Deal with Unlicensed/Illegal Payday Lenders - Step by Step Instructions
How to Deal with Illegal Loans..OhioGal's Primer http://www.debtconsolidationcare.com/paydayloan/dealingwith-illegallenders.html SOL for all states http://www.debtconsolidationcare.com/statute-of-limitation.html
If your name is not on the account, then you are not liable to pay. Since he's not working, they can't garnish any wages (if you're in a state that allows garnishment). If he's collecting unemployment, SSI they can't touch those funds. I'd hold on to your money and put it to better use.
If you do decide to pay it, you need to be certain you are paying to the right people. You can call the phone comany and find out who they turned the account over to. Maybe you can work out monthly payments to the phone company. It's worth a try.