Why don't you just call them, and offer a settlement? Offer them $100 to walk away from the whole mess. I find most businesses are prepared to cut a deal, they don't want to send your account out either.
Agreed.
State that you won't be returning as you don't believe you were treated respectfully when you broached the topic, thus you reacted accordingly. But offer $100-$200 to make it go away. State you will mail in a cheque within the next week (maybe two).