Product: Debt collection

I received a letter from a collection agency named Paramount Recovery Systems , L.P . The letter was dated XX/XX/2020 but the actual date I received it was on XX/XX/2020. I wrote a reply letter to them on XX/XX/2020 and mailed it the next day. We have been in the COVID-19 pandemic for several months now and mail deliveries are not always on time but I expect that my letter would be delivered to them during the past week. In any case, I have responded within 30 days after receiving their letter that was delivered to me. However, when I logged into my XXXX XXXX XXXXo check my credit report on XX/XX/2020, I noticed a devastating 60 point drop in my XXXX  credit score and there were THREE simultaneous derogatory reports filed by Paramount Recovery against me - I am filing a complaint against this entity for committing abusive and unfair collection practices. 
First of all, I received only ONE letter from them ( 1st attachment ) and in it in the amount they claimed that I owed and attempted to collect from me was {$1000.00} in ONE amount from a creditor named XXXX XXXX XXXX XXXX which I have never heard of. In the 3 derogatory remarks to XXXX, the creditor had suddenly changed to XXXX   XXXX XXXX and in THREE separate amounts of {$500.00}, {$790.00}, and another {$500.00}. 
I have no idea what these charges are and I was not given full 30 days to respond to this matter BY LAW and never received any notifications at all that there were this many debts that whoever it was that claimed that I owed or from where??? If this is not abusive, unfair and ILLEGAL debt collection practice, I dont know what is?? If they want to collect not one but three amounts for me shouldnt I at least be given a FULL 30-day notification period legally what these charges were regarding at first first?? And whats with all these different names of creditors coming out of the woodwork all at one time?? 
I dont mean to sound redundant but unless we have been living under a rock Im sure everyone is acutely aware that the whole country and the whole world have been immensely impacted by the global pandemic COVID-19 and I have been one of the untold millions that has been suffering hardships during the pandemic. I have been in poor health and also have been suffering economically and thats why it took me a couple of weeks to respond to the letter from Paramount Recovery but at least I had done it within 30 days of receiving their letter. And to have them not giving me ANY chance to even respond properly and fairly and just slammed THREE simultaneous derogatory marks on my credit report and decimated my good score by 60 points is not only illegal but also unusually cruel and heartless considering the time were in right now. 
Thats why Im turning to the Consumer Financial Protection Bureau to help me with this complaint - please hold Paramount Recovery accountable for illegal, unfair and abusive debt collection practices and please help restore my credit by having their false and unfair derogatory remarks removed from my credit report. My basic rights as a consumer of being given proper notification and proper time respond have been utterly violated. Thank you very much.