Product: Debt collection

I received a voicemail from a company called FJS Global. They said I was going to receive a summons at home or work if I did not contact them about this important matter. At the time I didnt even know it was about debt collection. I returned the call and was able to speak with XXXX. She told me about a debt that she said I had with XXXX XXXX XXXX from what she estimated was probably around the year 2000 or so. She couldnt give me a date. She could tell me what store the card was for either. At first she stated the original amount owed was around {$300.00}. Then she said with fees and all it was at around {$900.00}. She said I had to pay immediately to avoid receiving a summons. She said I should have received information in the mail from my XXXX XXXX about it. I stated I hadnt received anything from anyone about this alleged debt. She then offered me a settlement offer of {$700.00} to make this go away. She said I would be responsible for attorney and court fees if this went to court. I was encouraged to pay right away. She emailed me a form to put my credit card info on to submit payment and electronically sign. It was through hellosign. After viewing the document I was a little wary. She was still on the phone expecting me yo do it immediately with her still on the line. I told her I needed time to review the form and I was still at work so I would call her back. After work I tried to reach her and couldnt get her. She called me later that evening and I requested more information. I told her I wanted to check with the county to see if they ever sent a letter. She said they wouldnt be able to verify that for me because they wouldnt keep records of that. I also asked her to email me a copy of the letter that I was supposed to have received in the mail. It was called a demand letter. She sent it through hellosign too. The letter looked a little off to me. The original letter date stated XXXX but the body of the letter said XXXX. The amount on the letter said {$700.00} but she had told me the original amount was around {$900.00}. Also, this was supposed to be the original letter that was sent in the mail. If that were the case then why did it have todays date in the body of the letter. It just seemed strange to me. I told her I had went to their website and tried to obtain more information about my account but they the website link kept sending me to the XXXX home page. She hesitated and then said they were aware of the issue and had notified the secretary about it. There was also no contact info on the website other than the phone numbers and an address. I searched the address by XXXX maps and couldnt find this company listed at this address. Its an old area with a tiny strip mall with a roofing company and a chiropractor. No email or online contact information. I told her I would investigate further and call her back. I went online and found that a debt collector cant sue someone over a debt that has exceeded the statute of limitations in that state. Also, I still wasnt sure it was my debt. I called back and left a message stating this and have not received a return call at this point. The most worrisome thing about this is that she had my name, birthdate, current address, old address, and last XXXX of my social. This whole situation feels extremely strange to me. Is this a legitimate company or a scam?