It worked for me on my last attempt. Call, call, and call again. Ask for a goodwill. I let them know I wasn't even sure the debt was mine and I was just trying to fix credit. Tell them you didn't know about PFD, but heard companies can make a GW correction.
They really don't have any incentive to help. I just finally got the right kind heart on the phone.
Be as polite as possible, of course.