Please be advised that they do not offer refunds or exchanges on 'Final Sale' items. 'Final Sale' items are final so they recommend choosing carefully.
For exchanges on promotional/discounted items (e.g. orders that have used Welcome Offers), they allow exchanges in size for the same product/colour only. If you are after an alternative style or colour for the item(s) you want to return/exchange, you will be issued with either a refund or credit note for the actual price paid (so price less any discount codes used at the time of purchase).