I rented a toy hauler from Happy Camper on May 1, 2008. About 50 miles out of town on May 2, 2008, we stopped to check a tire and saw it was flat. We read the policy/procedure document given and it stated we needed to call the office and if someone was available, they would come fix the problem. I called and talked to a man and he apologized for not checking the tires and said to "Do what you have to do." We then called a towing company and paid $80 for him to change the tire (We would have changed it ourself, but we didn't have the right size lug-nut wrench.) When he got down the spare, it had a large piece of tread missing, so we put it on anyway and drove to a nearby tire store and purchased two tires at $120 a piece. We saved the tires so the owners could see how bad they were, the serivce associate at the tire store told us the tires were bad and you can't always tell with trailer tires because the tread doesn't wear like regular auto tires. After returning the trailer to the owners on May 6, 2008 (who were not at the office and told us to leave it in the back), the owners refused to pay the full $80 for the tire change, and are only willing to reimburse for the bad spare "taking our word that we didn't cause the damage ourself." I tried to explain that we would have changed the tire if we could have, and if they wouldn't reimburse us for the other tire, I wanted it back to try to get a refund from the tire store. Michelle stated "legally the tire was now theirs, so no."Resolution Sought: I would like them to reimburse the other half of the tire change ($40), and pay for the other tire ($120). If they won't pay for the tire, then let us have it back to try to get a refund from the tire store, or maybe sell it.