NPS GROUP Debt Collection Complaint

NPS GROUP Debt collection department,

I do not know Taking/threatening an illegal action Threatened arrest/jail if do not pay Kansas

NPS, - - -, continues to contact my cell phone. I have spoken with them once, whereas they refused to provide me with any information about who they were collecting for, but told me if I did n't send them $4000.00, I would be served with papers the following day. They would not verify the name of the credit or provide me with any information that this was a valid debt. I sent them a letter asking them to verify the debt and also to cease communications with me and anyone associated with me. I have not received verification of the debt and they have continued to call. Today, they called my office and when I told them I could not speak to them at work, they said " Find, we will contact your Human Resources and start garnishing your paycheck. '' They did then call my Human Resources but then hung up on them.