Ace- you can try that. But what has worked best for me, and I have had many many many med collections deleted, is this:
First, call the CA. Ask under what circumstances they do PFDs. Does it need to be authorized by the OC or do they have the authority to do it themselves? A bit of fact-checking will help you know where to go next.
If they're willing to PFD with them, just get it in writing & go from there.
If they're not willing, your next step is this:
Call the OC. Explain to them your situation. If it's really out-there and major, I've found many of them willing to delete. Tell them you are able to PIF, but you really want to recover from this bad sit, and can they authorize to delete? Let them know you're ready to pay ASAP and will even communicate over email (so you can get the PFD info in writing for your records) to get it taken care of as soon as possible. The possibility of big money in the near future is a fantastic wheel-greaser.
I had two CAs tell me they needed the OC's permission to delete first, and I let the OC know that I knew their permission would be needed, hence the phone call...
ALWAYS speak to a supervisor at both the CA & the OC. I tried it with two OCs on two separate occasions before I wised up & asked for a supervisor right away. Do a little recon: First phone call, just don't ID yourself & ask "who's the supervisor in that dept?" Innocuous enough.. next phone call, maybe a day later, call & ask direct for Supervisor's Name. When asked for nature of your call, tell the CSR you've been working on a situation w/ the CA & OC (or vice-versa) and the supervisor is the point of contact you've been given 
Of course after all is said & done, get it in writing!!!