Debt collection after move out and properly closing my account . Totally unacceptable

This is totally unacceptable. What an intentionally horrible way of handling moving out. I called and did everything right. Had to wait and then talked to a guy for a long time to go through the process of closing my old account. I also paid or agreed to pay the amount of $18 i believe as a remaining balance of the move. Now I receive a debt collection notice of $56! I just paid it now just to avoid wasting my time trying to talk to a human being. You make every process so long and difficult except taking our money. Why don't you have a smoother process for move out? Why isn't it easy ans clear to cancel/close an account ? You should do a better job.