National Credit Systems,Inc. Debt Collection Complaint

National Credit Systems,Inc. Debt collection department,

Other (phone, health club, etc.) Disclosure verification of debt Right to dispute notice not received California

In the year 2013 my family and I lived in - - Apartments and paid the first month of rent, and the deposit. We always paid the rent for a year since the apartments were under contract. We never missed any payments and the water payment ; we paid it full. I even have proved that we paid it all. I have the confirmation number that we paid it. Recently, I received a letter from the National Credit Systems , Inc regarding the deposit that we did n't pay. The amount is $690.00. They have sent me to collection without any warning or any prove that I owe that amount. In the letter it says they have already reported this collection to - national credit bureaus. Please I need your help to clear my credit and erase this debt that I do not owe.