Options after a customer refuses to take delivery of an order

I was wondering if anyone has experience with or knows your options when a customer rejects delivery of an order. In our situation, we are not operating on a specific contract with the customer but under our standard T&C's with a written purchase order from the customer. The product was made to order for the customer then shipped to them via sea freight. They have decided they no longer want the product, weeks after it shipped, and refused delivery. Our T&C's state that no product should be returned without our written consent. However, they do specifically adress canceled orders or rejected shipments. In this case we don't believe our customer is working ethically or in good faith. Normally we would work with them to find a solution and/or take the product back and charge them a re-stocking fee. They have made it clear that if we charge them a re-stocking fee they won't pay it anyway. The incoterm was DDP. We made the product available to them at their warehouse but they rejected it. The way I see it our only real option is to sue them for breach of contract because their P.O. and acceptance of our T&C's was technically a contract.