National Collection Systems, Inc. Debt Collection Complaint

National Collection Systems, Inc. Debt collection department,

I do not know Disclosure verification of debt Not given enough info to verify debt Missouri

I have repeatedly requested that National Credit Management provide me with an explanation of the amount they claim I owe, how that amount was calculated, account history. They have refused to provide this or any copies of documentation that this debt is in fact mine. Yet they have been willing to put this unverifiable debt on my credit report, as well as send me a continuing stream of collection letters. Please see attached.