Here at Db, we work very hard with our warehouses to ship your order as quickly as possible.
Due to this, we are unable to change any orders made on our system once they have gone through the check out process. This is because your order is immediately transferred to our warehouse which allocates our stock and sends the shipping details to our carrier.
Please see the following screenshot with the text highlighted during checkout:
If you've ordered the wrong product/color/quantity, you can initiate a return after the delivery has been made. In the meantime, you can place a new order for the correct item(s).
For information about how to return an order, please see here: I want to return my order