National Credit Systems,Inc. Debt Collection Complaint

National Credit Systems,Inc. Debt collection department,

Other (phone, health club, etc.) Cont'd attempts collect debt not owed Debt is not mine Washington

My previous place of residence never notified me of an outstanding balance I had with them by phone, mail or in person. When I moved out and turned my keys in to my landlord he told me everything was taken care of and never once did he mention anything about still owing the apartment $400.00. I was n't aware of any outstanding balance with my previous landlord until 6 months after I moved out when I received a letter in the mail from a collections agency telling me they were processing this account to be placed on my credit history. I tried contacting the apartment manager to discuss what this $400.00 fe was for and was unable to reach him. I still do n't know why I owe this amount and never did i recieve my deposit back either. If I am unaware that I owe any amount of money and never notified what the fee was for how can I pay it before it goes to collections and ruins my credit preventing me from renting or finding residence anywhere else.