Herrasment

I keep getting these calls saying that I owe $17,000.00 for loan from CITI Bank in 2005. First of all I do not owe CITI bank any money. I called CITI Banks told said this is not a company that does collections for them and it is most likely a scam. Now these people claim to be sending me law suit papers from this company. When I got the call from the County Carrier Service today I called them back and no answer. There is always someone at my home to sign for mail for me. These people are crooks and I told them take me to court. These people can have me severed through the Denver Sheriff Department. To this day I have not received any paper work from them about this collection from 2005.