Received a Delinquent Utility Bill on a condo I so...

Received a Delinquent Utility Bill on a condo I sold over a year ago. I inquired about the bill and was told that I had an another active account so they attached the bill my tenant (no, the NEW OWNER) bill to my account b/c they did not have any information on the owner. I did everything including closing out the account when I sold this place, I am on my way to see PWC right now. May have to get an attorney involved, it's the principle. Their problem that they did not receive the accurate information on the NEW OWNER... If there was another power company available, I would surely not be a customer of this one...