This depends heavily on the communication between everyone involved, but once you submit a return/exchange request, you can generally assume it will be processed within 24h-48h. Once it is processed, shipping times can vary depending on where you are based, so it is hard to give an exact estimate of how long this might take.
For exchanges, you can count on our standard shipping estimates to anticipate how long it might take for us to ship out a new item your way. Once we receive the item to be exchanged at our warehouse and have checked it for any damages and its unused condition, we will make sure to send out the replacement immediately. You will also receive another shipment confirmation email containing the tracking link for this replacement item being sent out.
In the case of a refund, once the returned item has arrived at our warehouse and has been checked for damages, the refund will be issued to your original form of payment immediately. It may take up to 3-5 business days for the money to be back in your account, depending on your bank provider.