In Europe we process exchanges and returns through Paris and Istanbul. In the United States we process them through San Francisco.
Returns/exchanges are only accepted where the product is returned unused/unworn--i.e. in pristine condition--within 15 days of delivery.
The customer is usually responsible for the cost of shipping for both returns and exchanges; however, in the case of exchanges we often ask that the customer pay the cost of the product's return shipment, whereas we will pay the cost of shipping its replacement.