Well, that's definitely NOT the way it's supposed to work. Negative information is supposed to come off after either 6 or 7 years depending on what it is, except for second bankruptcies which are reported for 14 years. Whether you a make a payment or not has no effect on the negative reporting period. Obviously, there's been an error and some phone calls are in order. See page 10 of the link below.
By "Date of Last Activity" Equifax means the date the debt went into original default, whether or not a subsequent payment was ever made on the account. Ditto for TransUnion. In practice though, they use the last payment date before the "Date of Original Default." Yes,I know it's confusing, but the bureaus designed it to be that way. See page 10 in the link below.
http://www.fcac-acfc.gc.ca/eng/resources/publications/budgetMoneyMgmt/CreditReportScore/PDF/CreditReportScore-eng.pdf