Product: Debt collection

Male callers from Merchants and Medical Corporation have been calling my father, who is recovering from XXXX, in regards to a debt they claim he owes to XXXX XXXX. He has never received an invoice stating the debt was owed or to be collected, neither from XXXX or the debt collection agency. The 1st call came XX/XX/2016 and my dad apparently told the guy to call back when I got home from work because he does n't handle the bills due to his condition. This guy called back ( ca n't recall his name at the moment, maybe XXXX or XXXX ) but when I asked about information regarding the call and the debt, the male caller became irate with me because I would n't agree to provide my father 's debit card information over the phone. He agreed to send an itemized invoice so we could confirm the service ( he would not provide a specific date for the alleged service ). He was very rude with me. We never receive an invoice. 

Last night ( about XXXX ) our house phone rings with a number we do n't recognize. A man named XXXX asks for my father and does not repeat where he 's calling from but insists that he speaks with my father. I give my father the phone and due to the volume being turned up for my father 's hearing I can hear XXXX 's loud voice telling my father he owes a debt for over {$1000.00} and my father gets upset and says " What?? '' Being XXXX patient, he does not need to be surprised, alarmed, etc So I took the phone from him and politely said hello and XXXX with an attitude says " Who am I speaking with NOW? '' I say it 's XXXX again and he asks my relation to my dad and I explain why I am taking the call. He says he can see on the file that i am authorized to handle this matter and asked for me to remit payment over the phone for the debt. I told him about the last phone call and how we never received the itemized invoice that was requested and that I again did not feel comfortable supplying my dad 's card information over the phone. I asked for contact/call-back information for the company and was denied and also denied permission to speak with a supervisor. XXXX started talking over me when I said I was n't giving the card info until we received the invoice and said they already sent one and would not be sending another. He continued to yell about what would happen if I did not remit payment and I yelled back that I would not be threatened and my father would not be threatened and legal action would be taken if the harassment would not stop. He continued to yell at me so I hung up the phone. 

I called the number back 20 minutes later to see if I could connect with a supervisor or identify the company ( I was not given the debt collection agency 's name prior to the callback and speaking with the supervisor ) I spoke with a young lady XXXX XXXX and informed her of what just happened and asked to speak with a supervisor. She incorrectly identified me as another person which was strange, and upon speaking with the supervisor XXXX XXXX she admitted that there was incorrect information on the file and the invoice was sent to another address on our street which now leads me to further believe this is not our debt and from previously being serviced by XXXX, they mixed my dad 's contact info with another patient on our street. I suggested that XXXX look into this employee XXXX and his tactics and she just kept saying she 'd listen to the recordings. No apologies were offered or anything additional as far as reprimands etc.