Received multiple calls - no message left

So I received calls from this number a few times and finally was able to catch it. I asked for a document and he refused to resend it. I asked for a manager and he got very nasty with me. I asked why I couldn't speak with one he said cause I'm telling you so. He was a sh@$head. He told me he would take care of it and hung up on me. I just didn't feel comfortable giving my financials out with no doc.

Recvd a call from this number on land line.  No message left. Called Id said Pete Verda Fl.

This is a.r.m. solutions a bill collector,  collection agency.

Says they are a debt collector (ARM Solutions) but they are representing a company I have done business with but do not owe an outstanding balance to. The caller did issue a threat that the company "will not stop until the debt is collected" when I requested documentation of the debt owed (which was not sent to me as requested).