I would also consider legal proceedings to sue the collection agency for falsified, slander and misinformation. The collection agency along with the CB will be facing a hefty penalty ($1000-$3000) payable to "you" if they do not correct and you win. I may also steer away from providing the proof of payment to the CB for (awhile) due to the fact that I would rather see the negative account disputed and then deleted than for it just to be updated as PAID...
If that does not work, pursue with legal actions according to FTC regulations.