Robert advise is very good, but, instead of you contact them, go to any/all credits bureu such as transunion.com, experian.com and equifax.com and do an account disupute. The burea will do this for free. If company that has the debt on your credit report do not answer, it will be deleted from your credit report. It is not a good thing for you to contact them since some of this unsattle accounts will be re activated and will pursue for a payment. ussually if no contact is done debts have to disapear unless debtor "re activates" the debt by contacting the and "saying" "I owe you".
7 years ago I dispute a mortgage information staying that I owned the property with somebody else but mortgage company never answer the credit bureu and trendline was deleted from that burea.
I hope you get yoru credit clear.