Help please Incorrect default date credit files

[Gixxk8]

Hi all. I defaulted on an unsecured loan back in november 2010 ( i checked this date with the original creditor yesterday who confirmed it). since 2010 i did pay off some of the loan and the last payment was made in jan 2013 through a debt management company. My problem is that the default date on both my credit reports equifax and experian show the default date as august 2011 with the name of th DCA. I want to change this date to the correct date as i want it off my reports in november 2016, not august 2017. How do i go about this? Is it the original creditors duty to change this or the DCA'S? Also i assume by contacting the DCA i will open a can of worms and have to start paying the debt again. If i contact the CDA, can they refuse to change it back to 2010 ? or can i come to an agreement that if it is changed back first then i will start paying?? Apologies for the probably silly questions but i really have no clue as to the best course of action. The outstanding balance is £6860 of the original 11k loan. Could i expect much of a discount to get rid of the debt bearing in mind it is near the end of the 6 years and will disappear off report anyway? If this default drops off next november my credit file will be finally free of all negative issues and i can apply for a mortgage, which is why i did not want it to be on my reports for almost another year. Many thanks for any help it is much appreciated.