I have benefitted so much from all the info I have learned so far on this forum, but still having trouble getting this one cleared up. Any help would be much appreciated!
I defaulted on a student loan (private loan) through Key Bank/AES (servicer had been AES). The total amount owed was about $25K, I settled it with Key Bank around August 2015 for $8K with the promise in writing they were to report to the 3 CBs it was settled. This part is all good. 
My 3 CB reports show several listings for my student loans, ONE is my current loan with Key Bank/AES that is in good standing that I am still paying; TWO is the Settled CO, which is reporting on all 3 CBs as Zero balance, paid/charge off or settled (the language varies on all three, but all three report a zero balance). THREE is the problem: all 3 CBs list a third account which I can tell is just a duplicate of the one that was settled/charged off. The balance amount is showing as if I still owe $25K and haven't made any payments; the account is listed as late, charge off, etc. One 1 CB it is called Key Bank, another has it listed as Society National PHEEA (which I googled and found that this was the prior bank name that was acquired or merged with Key Bank some years ago).
When I settled with Key Bank, I spoke to the same rep 3 times, have his name and he assured me that I do not have any other outstanding loan that maybe I lost track of or something, as if that was the case, I wanted to settle everything all at once. (Surely they would have been happy to take my money if there was another account). Rep said no, must be a duplicate on my CB reports and just ask the 3 CB to delete the duplicates.
I have since written letters to Key Bank requesting they remove the duplicates; no response. I emailed them on their Customer Service email system, followed up with proof of the settlement by fax and copies of the CB reports showing duplicates, no response. 
I have myfico, CK and CCT...should I use the online dispute features on one of those to dispute with the CBs? Or Call? or ?? I was afraid to make a mis-step - trying to buy a house next year and working at getting these uglies off my reports.
Any advice?? And thank you in advance!
IceinJuly, thank you for the reply! So you think the "duplicate" will just fall off naturally? I hope you are right. I was very grateful they pretty quickly (within a couple weeks) reported the Settled/Paid info and then I got the Zero balances showing.
As for the "duplicate" listing: Each CB calls it a different name, i.e. one is Key Bank, one AES and one is Society National PHEAA, but hopefully they will just drop off.
Your note reminded me that one of the CB comments does say "transferred to recovery". And the info seems to have been updated in July of 2015, when I was in the midst of my settlement discussions with Key Bank (June 2015 - Aug 2015....took me a couple months to pin down a number and come up with the money).
Thanks for your input
RobertEG, Thank you for the advice - I will do a direct dispute with each CB. I have never done one of those before so not sure how to do it. Do I need to do that on each CBs' own website? Or access the "dispute" link on CCT or something like that?
I really appreciate the tips! 
p.s. I found the direct dispute thread 