Daniel Martin and John Duke contracted with J & S Distributors, Inc., to purchase a KIS Magnum Speed printer for $17,000. The parties agreed that Martin and Duke would send one-half of the money as a deposit and would pay the balance upon delivery. When the machine arrived five days late, Martin and Duke refused to accept it, stating that the company had purchased a substitute machine elsewhere.

Martin and Duke requested the return of its deposit but J & S refused. Martin and Duke sued Jeff Sheffer and J & S for breach of contract, fraud, and breach of good faith.

The defendants counterclaimed for full performance of the contract pursuant to a clause in the contract which provides: In the event of non-payment of the balance of the purchase price reflected herein on due date and in the manner recorded or on such extended date which may be caused by late delivery on the part of [the seller], the Customer shall be liable for:

(1) immediate payment of the full balance recorded herein; and

(2) payment of interest at the rate of 12 percent per annum calculated on the balance due, when due, together with any attorney's fees, collection charges and other necessary expenses incurred by [the seller]. What are the rights of the parties?