Product: Debt collection

I was contacted by a person named XXXX XXXX, he somehow was able to contact me by cell phone. He said he was calling from a lawfirm ( unnamed ) on behalf of a company that purchased a debt from XXXX XXXX XXXX. They provided me with the phone number XXXX and case number XXXX. I had my daughter call them to follow up. XXXX spoke to her, they said to her that they were looking to serve her papers for a court appearance for a debt due and garnish wages. She asked for more information but he immediately responded that he was not able to provide anything over the phone, she asked for ie ; the name of the purchaser, the account number, amount due, time of when the debt existed, if it was inside of the statue of limitations for the debt collection, and how to settle. XXXX responded the debt was from XXXX, with an original balance of about {$650.00}, with a now current balance of over XXXX XXXX for fees and attorneys fees. He informed her a letter was sent to the house from the collection agency in XXXX XXXX to provide her with options to settle the debt. No such letter was ever received. He told her he could have her settle outside of court, pay {$800.00} or payment plan of the XXXX XXXX plus fees and would put the serving of the papers on hold for 4 hours, to be served at home and my workplace while we decide what to do. She agreed and he called back in XXXX hours to discuss what the decision was from the number XXXX. My daughter asked for a copy of an invoice of what is due, a copy of the letter that was sent but not received. XXXX got aggressive and refused to provide the settlement letter because " he cant just give that opportunity again ''. She told him she had no way in agreeing to anything or reviewing options if there was no paperwork to do that from. He agreed to send her a settlement letter, which I will attach here for reference. The name of the law firm is XXXX XXXX XXXX which I believe may be short for XXXX XXXX XXXX XXXX  with an address based in California. The letter contains the original company in which the debt is due, my name, partial of my address, and my social security number, along with the settlement agreement and form to submit my credit card payment. She called XXXX back to discuss why the address was incomplete, if we were to submit payment via the form. He said that's what was provided by the company, she pointed out that it would then make it impossible for the letter to have ever been received, he responded casually that that was normally the case, so improper informing of such debt and legal action confirmed. Upon research of the company, many scam complaints come up referencing the same person XXXX, for similar collections amounts, similar script. Example XXXX XXXX XXXX XXXX They look to be based out of XXXX XXXX. The rep XXXX XXXX may be an imposter, there is a lawyer in XXXX XXXX with the same name they may be imitating. My daughter contacted SHOPNBC, now XXXX, to verify the information the law firm has provided on the letter, while the name account number and social match, the balance amount, the incompleteness of the address did not match. The account has not had any activity since XXXX and was closed and deleted on XX/XX/XXXX, as per the XXXX  company. The number for the XXXX credit card company is XXXX. This is way outside of the limitation for debt collection, as well as incorrect amount, as well as a refusal to provide any account information by the law firm/collector, threatening of lawsuit and garnishment, as well as improper handling of private information. How did this law firm get my social security number, my old SHOPNBC credit card number, my name, and current cellphone number?