Product: Debt collection

On XX/XX/XXXX, I received a notification from XXXX XXXX informing me of a change in my credit score due to a collection on my account. When I reviewed the details of the collection, I did not recognize this debt nor the collection agency named Eastern Account System. I immediately looked up the collection agencys contact information via internet search and called them. I spoke with a representative and informed her that I was not aware of this debt. I asked the representative to check when I was notified of this debt and to check what the method of communication was. She said that the only communication from them was one letter sent via email to inform me of the debt in XX/XX/XXXX. I informed her that I never received this email or any emails from them. I also asked if they have attempted to call me to inform me of this debt and she said that they do not call people, they only send one letter via email to inform people of their debt. I asked her to confirm the name of the company so that I could enter it in my emails search bar, she confirmed the name and I typed it in and still could not find any emails from this company. I informed her of this and she asked me if I checked my spam and junk mail and I told her that I did and still couldnt find this email. I asked her what the email address is that they have on file and she rudely said um the email address that was provided to us. Your first and last name XXXX. I informed her that this email is correct and then asked her if she can provide me with proof that the letter was emailed to me because I can not find any emails from their company and she said something along the lines of no I cant provide proof. I see here that it was sent on XXXX XXXX XXXX XXXX XXXX time in a rude tone ( I forgot the details of the date and time that she stated ). After doing research, I learned that debt collection agencies are required to provide proof or additional information regarding the debt if asked to do so and she declined to provide me the proof that I asked for. She also did not offer to resend the letter via email after I informed her several times that I did not receive this email. All she did was dismiss my concerns, tell me the date and time the letter was emailed to me, discussed the details of my supposed outstanding balance with XXXX, and then asked me how Id like to pay the debt. I informed her that I am not paying the debt at this time because I do not recognize the debt and that I dont believe the debt is accurate as I did not receive any letters, emails, or calls from them informing me of this debt. She very rudely said something along the lines of I am not giving you inaccurate information. I can see your XXXX service statements right now and XXXX informing you that you owe this amount. I also informed the representative that she was very rude and condescending and that this is my first time dealing with a matter like this so she does not need to make me feel XXXX and have a condescending tone when I am simply trying to resolve this type of issue for the first time. Then she said Im sorry if you feel like Im being rude. I told her that Im going to dispute the debt since I did not receive any letter or communication from them regarding this debt.