Don't do it. Some of these bill collectors put the money in their own pocket and the creditor never sees it. See the post on whocallsme by ”Scam” (23 Dec 11) under 8043185476 for further information.
Also, these people have been known to severely harass people over the phone, so here is the information on how to block the calls-see my post on whocallsme under 3059182338.
I got a call from a Terry Burham stating that there were charges brought against me and that she needed to bring "sealed" documents to my location. This is a scam. They want you to put money on a pre-paid card in order to pay back this unknown debt.