Unfortunately, the facts are not in dispute. You admit you didn't pay it. So, there really isn't a way to have it removed, unless the creditor out of the goodness of his heart decides to remove it.
You can ask them, explaining your mistake and reminding them what a good tenant you were otherwise - try to appeal to their good side, but the creditor probably did not get full payment from the collection agency.
Filing a dispute may seem logical, but try to resolve it amicably first. (And say your sorry.)
If humility fails, you can, however, file your own comments attached to the negative item. That won't wipe out the item, which probably says paid now, but some lender might look at it.
Remember as the saying goes:
time heals all wounds.
You'll just have to wait it out, most likely.