Product: Debt collection

kept getting phone calls from weird numbers, leaving no messages. They called my dad 's ex wife on XXXX/XXXX/XXXX stating that i needed to call them and left a number XXXX she stated her name was XXXX XXXX. They then called me right after that i did not answer because I have so many weird numbers calling me they left a voicemail saying that XXXX needs to call us back at XXXX. Before i could even call the number back they had called my sister 's cell phone and left the exact same message. I then call the number back on XXXX/XXXX/XXXX at XXXX and asked what this was in regards to, she then asked if i would not say anything until she was done explaining what is going on. She was talking so fast I only caught bits and pieces of what she was saying. She said that she was ADR and that she was collecting a debt from XXXX XXXX XXXX which is funded by XXXX XXXX. She stated that they needed to collect on a debt i took out online. She said that if they were to press charges the charges would be Malicious intent to defraud a financial institution, Check fraud and theft of services and goods. I need to pay {$2500.00} and if this goes to court i will be charged another {$1000.00} dollars for attorney costs. They were calling to retain a statement from me the money was put into a XXXX account in XXXX. I then told her i paid that off last year, But i will be honest I 'm pretty sure i got scammed because i was so scared i was going to jail. She said well did you get a receipt i said no i did n't and the company wouldnt return my phone calls so i just gave up. She stated that they need to send you a validation letter with the debtor name and the original amount along with the amount you owe. I said well i never received anything. I asked her if she could send a validation letter and she kindly said yes i can. I said ok, because I honestly do n't think I owe this debt but if i do i will pay it. She then got snippy with me and said that people retain them because they have not gotten paid for the service they provided and usually it sits in their collection agency for 2 or 3 years and then they contact us and sue you for a lot of money. She then asked how much i had to pay the other people i said {$2000.00} dollars and she said thats crazy someone scammed you because I 've never seen any accounts in here over {$510.00} I said well you are asking for {$2500.00} thats over {$510.00}. She then stated well i hope you find out who scammed you for {$2000.00} dollars and hung up on me. Now i get phone calls from unavailable numbers to my cell phone and my sisters this gentleman XXXX XXXX and he is just letting me know that he will arrive at my place of employment or my residents on XXXX XXXX to deliver legal documents. If i have problems i can contact the plaintiffs office at XXXX case number XXXX then when he repeats the number its case number XXXX. He has called repeatedly on my sisters phone leaving XXXX voicemail for me XXXX/XXXX/XXXX and XXXX/XXXX/XXXX. He has also called me and left messages XXXX ( 2 times ) XXXX. I am not giving any money to them. I do not remember taking out a loan with them at all but they stated that it was in XXXX at my XXXX XXXX account and in XXXX i did have a XXXX XXXX account. This is how they got me last time, they knew all my information so i assumed i did take it out. But when i go back I do n't see anything.