Product: Debt collection

XXXX/XXXX/2015 XXXX I received an alert that my credit score had dropped and upon checking my credit report I had seen that there was a that bill was was reporting as in collections by the BYL Collections Agency at XXXX XXXX XXXX XXXX XXXX XXXX , PA. I had no recollection of what the bill was, or if the bill was mine. I had not received a letter or phone call notifying me. 
Upon calling BYL at XXXX at XXXX, XXXX/XXXX/2015. I was advised of the balance and the hospital in which it originated. The adviser said a letter may have been sent around the XXXX time frame notifying me they had my account. I was given the option to pay it off, but without knowing the specifics of the bill to ensure it was mine, I was not comfortable paying. When asked why no one called or sent another letter due to lack of my response, she said they did n't need to and might send another in a year ( A YEAR ) after the initial letter. I felt it was unfair that my credit was negatively impacted by an outstanding bill I was unaware of. She agreed to send me another letter, after verifying my address. Unhappy with the resolution, I asked to be escalated. 
When transferred to a 'manager ', XXXX , I was told she did n't need to validate that the debt was mine. She told me that she sent a letter in XXXX, gave me three months to respond, and then put it on my credit. When I advised I did n't receive a letter and felt it was unfair that it was reported without validating the debt was owed to them first by me, she told me it was 'my problem ' and that once she sent a letter, she did n't need to send another XXXX. She just had to send the letter, and what happens to it after she sends it is n't her problem. I said that once I verified it was mine, I was happy to pay it, but could n't have known I had the debt without notification. She was rude and condescending and not being comfortable with the resolution that it was just 'my problem ' and not hers, I asked to be escalated to her manager or a complaints resolution channel. 
The 'Collections Manager ' refused to give me the name of any higher point of contact ( i.e. her manager, or her manager 's manager, or any higher point of contact at the agency ). She said there is no Executive Office or any channel to file a complaint or have a complaint resolved. I was given the address where I could send a payment. Basically, if I wanted to file a complaint against her, I would send it to her. 
In all my years as a consumer, I have never been treated so rudely by a 'professional '. 
My main concern with this issue is that other consumers may fall victim to the same unfair and deceptive treatment and negative impacts I may now be facing due to the negligence and careless treatment of BYL. Currently in the process of applying for a mortgage for a home for my son and myself ( the reason I was alerted of BYL reporting an account I was unaware of on my credit ), I may now be unable to get a mortgage for a home for my son and myself, and I could potential be losing XXXX of dollars over the lifespan of a mortgage loan ... due to a bill I was unaware of, which I would happily pay if notified and validated as mine. 
There was no contact made to me via USPS, phone, fax, email, etc. prior to this reporting to the XXXX major credit bureaus.