Yes, deletion of old accounts can negatively affect your scoring under length of credit history by removing your oldest account and/or reducing your AAoA.
Why were they deleted?
Did the creditor report deletion to the CRA, or did the CRA delete for some reason, such as having reached a deletion age after closure?
Information that is deleted from your credit report will normally not be reinserted by the creditor or CRA, as the deletion was for their own purpose.
Regardless, you must first determine who to contact.
