If the date of last payment on these accounts are over 7 years old, the Collection Agency is not allowed to re-list them on your report because the collection agencies have to follow the date of last activity.
If the date of last payment on these accounts are < 7 years old, then the collection agency is allowed to list it on your report.
In either situation, double-check to make sure that they did not re-date the date of last activity.