Swampy likes the reference Peekawho posted. A charge off is an accounting maneuver, it does not mean that you don't owe the debt.
Here is the problem. The charge off goes on your credit record, as does the collection agency when it buys the debt. When you pay the collection agency, they'll take off the collection agency record (mark it as paid).
The charge off can't be removed, or marked as paid, because there is nothing to pay as the debt has been sold. Its something that happened. You have to wait the seven years or however long.
This happened to my SIL. She paid a collections agency, and STILL cannot get the charge off removed, or even marked as PAID.
I think that it is wrong that they allow these companies to sale the card debt like this. I now have 4 collections on my credit from ONE debt.
I found this about charge offs, don't know if it will help.
http://www.bankrate.com/brm/news/debt/20021216a.asp
I gather the term "charged off" refers to the Credit Card Company cancelling the use of your card so you could no longer use it, but you still had an outstanding amount owing on the card?
If that is the case, it is perfectly legal for any company that is owed money and has not recieved payment of same to "sell" the debt to a Debt Collection Agency.
My advice would be to enter into some form of payment arrangement to get the debt paid. The longer the debt is left unpaid the more interest you will end up paying. Unfortunately the debt will not simply go away by ignoring it.