I sold a horse using a handwritten contract; state is SD, the contract stated acceptance of a $250 nonrefundable deposit to hold the horse (not to sell to another until they could get the money to pay for the horse) The buyer of the horse did not have the money and would receive it in 45 days. The horse was sold as is, with the option of a vet check if they so desired. The horse was found to be slightly lame on one leg. The buyer did not want to buy the horse, I had waited for three weeks to get them to do an exam. It was orally agreed to do the exam ASAP. Board was also to start the day following agreement. The contract was handwritten and they want their (stated) non-refundable deposit returned. What, legally, am I obligated to do?