Product: Debt collection

Hi there, My fiance and I rented an apartment at XXXX XXXX   in XXXX XXXX, ND from XX/XX/XXXX to XX/XX/XXXX.  We had signed a one year lease and had to move out of the state for health reasons. We were told by XXXX XXXX  to find a replacement tenant and that they could take over our lease at the same rental rate we were paying until XX/XX/XXXX, as long as their application was approved. We found someone that was approved by management and everything was set for that individual to take over our lease on XX/XX/XXXX. We also stated we would be cleaning our apartment ourselves and the manager had someone come in to clean the apartment while we were still moving out, even though we communicated that we would not be paying to have someone clean the apartment. While moving out, the manager called me and stated that the replacement tenant " may not work out '' because his XXXX photos had skulls in them and they were " scary. '' I was told a few days later by the manager that the replacement tenant was no longer going to be taking the apartment ( even though he was trying to pay his first month of rent and still wanted the apartment ) and that the manager would be able to find someone to move into our apartment within one week of us moving out. I never heard anything else from XXXX until the end of XX/XX/XXXX when the manager asked for our new address. The manager stated we would have some " move-out '' charges and apologized. I received a bill two weeks later for XX/XX/XXXX rent and cleaning fees, etc. I tried contacting XXXX and XXXX XXXX XXXX ( who manages XXXX ) throughout XX/XX/XXXX and XX/XX/XXXX, which I also have proof of. I was trying to dispute the charges based on the evidence we had in communication with the manager saying we would owe nothing further. I would have been happy to pay the charges if I could have spoken with someone and worked something out. However, I received no return phone calls or emails from XXXX XXXX XXXX. In XX/XX/XXXX, I received an alert, saying my credit score had decreased by 60 points. I am in the middle of purchasing a home and this was very concerning for me. I investigated why my credit score had plummeted and found that XXXX XXXX XXXX had sent our bill to collections. I received no communication from XXXX XXXX XXXX or from the collection agency ( United Accounts in XXXX ND ) about this issue. My fiance and I had many phone and email conversations with XXXX XXXX XXXX after finding out things had been sent to collections. XXXX XXXX XXXX said that there was nothing that they could do and recommended that we pay our balance with United Accounts. Since XX/XX/XXXX, my fiance and I have tried contacting United Accounts approximately thirty times in total ( XX/XX/XXXX to XX/XX/XXXX ) trying to pay our bill. We have left many voicemails for United Accounts with no return phone calls. We have taken screen shots of reviews of United Accounts on  XXXX, because many people have experienced the same thing as us and say that it is " impossible '' to get ahold of United Accounts. We still have received zero correspondence from United Accounts and never would have known that this went to collections if we had not been paying close attention to our credit scores. This is very frustrating and we have many emails and texts to back up all of these claims. 
Thank you!