Phila PA on caller ID.....left no message on answering machine

Who is this

bill collector

It was a debt collector Convergent Outstourcing Inc when I answered only to be instantly put on hold a recording plays while you are on hold, "Hello, please hold for the first available representative. It is important that we speak with you. We will be with you shortly."  Trying to collect on debt for 20 years ago and would not listen and I told him to cease and desist

they called me also with the same thing. but this was paid many year ago and is no longer on my credit report which is now clear of everyone but they are calling everyday to collect this debt that do no longer on any report. when told to verify the account and that I owe this . they said you do owe this and we want payment. when I told them to give the original creditor they refused and said make payment today. I told them to stop calling me but they still call. I am on the do not call list and will be suing them in a short time if they do not stop calling