Yes they can! If you want to make an exchange for a different product that has a higher price, you only have to pay the difference by means of a bank deposit or bank transfer. If, on the other hand, you want to exchange a product for another that has a lower price, we will contact you via email to let you know the method of refunding the difference.
In case you want to make this kind of change, please contact us via email at contact@kavelina.com