Product: Debt collection

On XXXX XXXX, 2016 I have requested in an email that Portfolio Recovery explain the reason why I am been sued and who I owe the debt to if any. On XXXX XXXX, 2016 I have received a letter regarding a lawsuit been filed against me Reference # XXXX. I do not have any outstanding debts and I am not sure why I am been contacted in first place. I also requested that XXXX to correct the issue and suspend further communications. 

XXXX XXXX XXXX , XXXX XXXX Disputes Department XXXX XXXX XXXX XXXX, VA XXXX XXXX : XXXX Dear XXXX XXXX XXXX , XXXX, You contacted me by mail on XXXX XXXX, 2016 and stated that I owe you the total of {$4200.00}. 
Please provide me with more information below to fully understand your claim : 1- Why you think I owe the debt and to whom I owe it, including : 2- The name and address of the creditor to whom the debt is currently owed, the account number used by that creditor. 
3- If this debt started with a different creditor, provide the name and address of the original creditor, the account number used by that creditor, and the amount owed to that creditor at the time it was transferred. When you identify the original creditor, please provide any other name by which I might know them, if that is different from the official name. In addition, tell me when the current creditor obtained the debt and who the current creditor obtained it from. 
4- Provide verification and documentation that there is a valid basis for claiming that I am required to pay the debt to the current creditor. For example, can you provide a copy of the written agreement that created my original requirement to pay? If you are asking that I pay a debt that somebody else is or was required to pay, identify that person. Provide verification and documentation about why this is a debt that I am required to pay. 
5- The age of the debt, including : A copy of the last billing statement sent to me by the original creditor. 
State when you obtained the debt. 
If there have been any additional interest, fees or charges added since the last billing statement from the original creditor, provide an itemization showing the dates and amount of each added amount. In addition, explain how the added interest, fees or other charges are expressly authorized by the agreement creating the debt or are permitted by law. 
If there have been any payments or other reductions since the last billing statement from the original creditor, provide an itemization showing the dates and amount of each of them. 
If there have been any other changes or adjustments since the last billing statement from the original creditor, please provide full verification and documentation of the amount you are trying to collect. Explain how that amount was calculated. In addition, explain how the other changes or adjustments are expressly authorized by the agreement creating the debt or permitted by law. 
Tell me when the creditor claims this debt became due and when it became delinquent. And identify the date of the last payment made on this account. 
Have you made a determination that this debt is within the statute of limitations applicable to it? Tell me when you think the statute of limitations expires for this debt, and how you determined that. 
Details about your authority to collect this debt. 
I would like more information about your firm before I discuss the debt with you. Does your firm have a debt collection license from my state? If not, say why not. If so, provide the date of the license, the name on the license, the license number, and the name, address and telephone number of the state agency issuing the license. 
If you are contacting me from a place outside my state, does your firm have a debt collection license from that place? If so, provide the date of the license, the name on the license, the license number, and the name, address and telephone