Product: Debt collection

I was first contacted by NCB Management Services on XX/XX/2017 at XXXX. I missed the call so I called back when I saw the missed call at XXXX to see who was calling me and in reference to what. I was connected by the company 's operator to a XXXX. She asked me for the last for digits of my SSN and my date of birth. Having been a recent victim of identify theft I explained to XXXX that I did not give out such information to strangers over the phone. I asked if she could send communication to me in writing concerning the debt. She said she would do so. She also told me that written communication had been sent out a month prior and they had been trying to reach me by phone for over a month. I knew this to be a blatant lie as whenever I see a missed call on my phone I immediately return the call to follow up. Moreover, I check my mailbox EVERYDAY and I had not received ANYTHING from a debt collector. I asked if she would send the information again and she agreed and informed me that she was ending the call because I refused to verify my information. She told me that my refusal would be notated. 
I have lived out of the country for several years and I was very concerned about having anything negative placed on my credit report. So after a few minutes I called back again and was connected with a male collector. I explained the situation with XXXX and told him that I was calling because IF I owe something I am not trying to run I simply want to gather the information and get back to him. He asked me to verify my address which I did. He told me that XXXX had lied and his agency had NOT received the debt a month prior but on XX/XX/2017. He told me that if was a very new collection so I should expect a letter in the mail in a few days. He told me that the address that he had on his file DID NOT have a include a apartment number. I gave him my address again and told him to please send written communication of the debt to my address. He said that he would have the letter resent. He gave me his information to follow up with him AFTER I received the letter. His name is XXXX at extension XXXX. I told him I would and ended the call. On today, XX/XX/2017 at XXXX I received another call from XXXX. Again, she asked me to verify my social security number, again I refused. She told me she could n't talk to me ... I told her what happed with XXXX last week and that I still had not received written communication of the debt. I told her if I did not receive written communication that I would report them to the Georgia Attorney General 's office, the FTC and the Bureau of Consumer protection. She said she would connect me to a manager. After a long wait I was connected to the manager who basically told me that he could not talk to me if I refused to verify my identify. I told him that is fine. I am asking for WRITTEN communication. Communication that should have been sent to me within 5 days of initial contact which was XX/XX/2017. He told me that they follow the rules and unless I verified my identify he could not communicate with me. I told him to PLEASE sent a letter concerning my debt to the address that I proovided to XXXX on last week. He then hung up in my face. I feel harrased and I know my rights have been violated. I am stressed because I do n't have any information about this possible debt and I do n't want this to ruin my credit. They keep calling me but will not furnish written information about the debt.