I sent a request for a verification of debt last week and am receiving multiple calls on my cell phone and at work through National Credit Services by a woman named XXXX. She has called my work multiple times and continues to contact me after I sent a written request for verification of debt. When I told her that over the phone she said the debt was from " x '' on " x date ''. I said that was not sufficient and I need actual verification of the amount and validity. She continues to call my place of employment.