<prompt> Human: We were renting a house, moved out and transfered all utitlies back to the owner. We were not doing well financially and moved to a much cheaper place to pay off bills. One of the first bills was a waste water bill. Where I live you pay to get water, and send water. It was big and one we just wanted rid of. We actually overpaid and got a check back for like 3. Anyway, jump forward 7 months and I get a call today from a collections company saying that I hadnt paid my bill in months and owed them 2,000. When we moved in the waste water was automatically put in our name based on the water and electric bills from my understanding. The former owner sold the house just a few weeks after we moved out. I dont know what to do. Obviously I feel like I dont owe the money, because I didnt spend it. Also my credit score is involved now and we just closed on a house two weeks ago. It took a lot to get my credit in order and I would like to keep it that way. The other issue I see is that I never got a single bill from them about this, even though my new address was used to settle the past due amount 7 moths ago. My 3 refund check was even sent there. Advice on how to move forward.  <response>: Youre going to need to provide your location. If youre in the US, you should send a debt validation letter. 