Complaint sub-issue: Didn't receive enough information to verify debt

I have tried reaching out to ProCollect Inc. multiple times in the past two months. The first time I contacted them was around XX/XX/XXXX ( not exact date ). I reached out to them asking them if they could provide me a settlement for the amount owed which is ~ {$2200.00}. This was NEVER the original amount owed. When they offered me a settlement of {$1200.00} the first time I called them I had requested a letter be sent to me in the mail verifying the debt and the representative Miss XXXX advised they are not able to send out letters before the debt has been paid. I asked to speak with a supervisor multiple times and was denied the right being told " this was not a supervisor matter ''. Feeling defeated, I had hung up the phone. A week later I has called back asking to see about another settlement. Again they offered me another settlement of {$1200.00} and I again asked for a settlement letter to be sent to me before I paid the debt. Miss XXXX stated again that they are unable to send a settlement letter in the mail before a debt is paid off. I asked to speak to a supervisor again and was denied the right. Miss XXXX advised this would be the final offer for a settlement and after this call, the only option would be balance in full. She threatened me and advised I had 3 minutes to pay off this debt or she would report to the credit bureaus as refusal to pay. I said I can not pay the debt without any proof on my end that this debt is going to be settled. Weeks go by and on XX/XX/2020 I had called ProCollect again. Miss XXXX has now been assigned to my file permanently. Every time I call I get connected with Miss XXXX. On XX/XX/XXXX I requested that a itemized bill be sent to my address. She advised that there would be a bill sent to my address and she did not know exactly when it would be received. Two weeks went by and I still had not received a letter in the mail. I called ProCollect back on XX/XX/2020 to see why my itemized statement had not been mailed to me yet. Miss XXXX advised the letter was mailed to me back on XX/XX/2020 and confirmed my address. The address she had on file was correct and I advised her I had never received a letter in the mail. She advised me to follow up with my local post office. I followed up with my local post office XX/XX/2020 and they are unable to find any records of letters from ProCollect Inc. being sent to my address. ProCollect has no proof or certified copy that they had sent an itemized statement in the mail. On XX/XX/2020 I had called back ProCollect to offer to pay my settlement offer of {$1200.00} with having received no proof over the past two months of being in communication with this company. Miss XXXX advised since I did not pay the first two settlements offered to me I am only able to now pay this debt in full which is double the original amount owed. Unfortunately I do not have funding to pay {$2200.00} to this company and have worked tirelessly in efforts to resolve this issue. I have been harassed and threatened by this company which has put an emotional and physical toll on my mental well being. They are practicing unfair collecting practices and should be shut down for harassment, threats and lies! They broke a law of the Fair Debt Collection Practices Act and never were able to validate my debt after 30 days of contact.I am disgusted with this company and the way they run things. Totally illegal scam artists!