that sucks. in my personal experience, I have never had them change the status of another creditor just because I disputed something. unless for some bizarre reason they have requested an update from each and every creditor on your report which seems odd again since I have not seen that happen either.
have you considered talk to them creditor and straight up asking them why they are reporting it as charged off when it has been in good standing for two years? see what they say and at the very least you might be able to get a failure to respond from them which might allow you to get it removed directly from the CRA.
Common Abbreviations|FDCPA|FCRA
Starting Score: TU:695 - EQ:719 - EX:630
Current Score: TU:712 - EQ:755 - EX:712
Goal Score: TU:800 - EQ:800 - EX:800