Product: Debt collection

On Wednesday XX/XX/XXXX I received a letter from Mitchell D Bluhm & Associates, XXXX attached ) saying I owed money. On XX/XX/XXXX I contacted their office letting them know that I had already paid this debt to the hospital back in XXXX. XXXX informed me that this particular hospital will send in more then one doctor and then charge you for each one and I probably paid for one and not the others that had came in. I dont recall having more then one doctor, and I let her know that when I was contacted by the hospital about this debt, I was told it was resolved then. She offered to settle the debt with me if I paid {$180.00} by Friday XX/XX/XXXX and said if I was going to dispute it I only had until that day for them to receive my dispute or they would put it on my credit. I immediately typed out my dispute XXXX attached ) and sent it overnight mail ( receipt from post office attached with tracking number and signature request on delivery ) on XX/XX/XXXX. I received the next letter on XX/XX/XXXX ( dated XX/XX/XXXX attached XXXX saying they had not had time to complete their investigation. During this time, they never stopped the harassing phone calls, my understanding is that they are suppose to stop the harassing calls until they send proof of debt. I received their validity of the account on XX/XX/XXXX ( dated XX/XX/XXXX attached ) but nothing they sent shows that I owe anything. It has a Current Statement Balance : {$0.00} and does not have any type of letterhead or any information about the creditor on the paper. It looks like they couldve typed it theirselves and printed it. I never got the address of the original collector, any details about the account, no response on if it was within the statute of limitations, nor anything about their authority to collect on the debt or any proof that any of this is legitimate. ( Attached picture of letter I sent them asking for all of this information XXXX XXXX called me on XX/XX/XXXX, she did not say who she was whenever I answered. XXXX immediately started asking me my personal information when I answered the phone. I only responded to yes when being asked if I was XXXX. She proceeded to ask my date of birth, address, and before she could ask anything else I asked who I was speaking with. She then told me who she was, and I asked that she disclose that before asking for personal information and that I didnt feel comfortable just giving a random person from a random number any of my personal information. She immediately became very rude, saying they had sent proof of debt, I told her what they sent I didnt feel was proof and I needed something saying that if I go and pay this, the hospital cant come and say I didnt pay it later on like what they are doing to me now. She ended up transferring me to someone else without even informing me she was doing so. The next lady was even worse. I did not get her name, but she was extremely rude and told me I dont pay your bills for you. I simply asked if they had bought the account ( like XXXX had told me they did XXXX if they could send something showing they own it and that the hospital cant try and collect on it later, basically showing they bought the debt and that I dont owe the hospital anymore. ( I never received anything with the hospitals name on it or letterhead through this entire nightmare ) Whoever I spoke with, ended up hanging up on me while I was speaking, I never raised my voice, used any type of bad language, or made any types of threats. I simply asked for something showing that this would be it if I did pay what I had already paid. The lady sent me another letter on XX/XX/XXXX XXXX attached ) with what she said was proof that they had the account. She simply sent another privacy notice ( attached XXXX from another company, not from the hospital nor her office. 
I am extremely confused on who is trying to collect the debt ( on their letters, sometimes the letterhead looks official and in color and other times their letterhead looks completely different and in black and white, also confused on how they are in XXXX, Texas yet sending me letters from XXXX, CA. ) I havent received anything that I asked for in my dispute and on XX/XX/XXXX I was informed by my credit card company that they ( Mitchell D Bluhm & Associates ) had put a major derogatory on my credit without ever sending me any kind of proof that this debt is valid or that they own the account. 
I have a XXXX year old at home with me, jobs are hard to find due to COVID, and the harassing phone calls and threats to ruin my credit are really getting old. Im not sure what I need to do from here, and really need help with this office. 
I also wanted to say I really feel like this is some type of scam, when XXXX had offered to settle with me, she said I had to pay with a card over the phone and they would not send me anything via mail. I have no idea if they are even a legitimate company, and nothing they have sent me shows that this is a valid debt. I dont feel right about giving someone my personal information and credit card number over the phone, especially whenever they can not tell me who they are when they call me.