They called about twice a day for over a month, never leave a message and if I answer there is no one there. One day I held on for about 2 minutes until someone came on and asked for someone whose name I do not know. They said they were a collection agency. I informed them that I had already filed a complaint about them on the do not call list, and asked why they call over and over with no one there. They said they have an auto dialing system that puts you on hold until an agent can come to the phone, and they apologized and said they would remove me from their list. If you are being harassed by these people and do not owe them money, file a complaint on the National Do Not Call list.
It's a collection agency for old bills. They called me twice a day for months, and never answered. Finally, someone did. He started the conversation with, "Do you still receive mail at XXX address?". When I prompted him to introduce himself, he did, sarcastically. So I told him that I do not receive mail there. He asked if it was an old address, to which I told him, "obviously". I asked him not to call again and send my proof of the bill using the USPS.