Interest based, principle-centered negotiation in my opinion is the correct approach in the case between the customer service rep Tina and the customer Maria. My first though after reading the situation was to put myself into the shoes of both Tina and Maria. While Tina has a job where she is to uphold the thirty day return policy, her job in no way is to insult the customer, this insult as well as the entire situation was witnessed by Joe. I believe in all honesty that Joe must handle this situation differently and cannot enforce the thirty day return policy. What Joe can do is apologize for the incident, explain the policy again and offer two solutions. The first of these two solutions could be that Maria contact the manufacturer and insist they either fix or exchange the product if it is defective or refund. The other solution if Maria is still not willing to go that route is to offer a store credit for the return. I would like to see Joe bend on the policy simply because of the insults by Tina. Had customer service not insulted the customer the policy remains a policy and can be enforced with positional bargaining, an apology for the rudeness and the fact that the store cannot honor the return because it is after the thirty days. This case with a store credit ends in a win/win situation, the product can be returned to the manufacturer or resold as a seconds on discount or however they deal with the returned merchandise, the store will also still have the fact that Maria has the credit, which is to be spent in the store in any case, so as not to lose a customer. Maria can make another purchase in the store on another item with her credit and may not discontinue being a customer.