No. Citing health and safety, L'Occitane won't take its products back or swap them, sealed or not. A return and refund is possible only when an item is faulty or you were sent the wrong one, and you need to take it up with customer service.
That's why it pays to study a skincare product's description and ingredient list before buying it for the first time. If something in your delivery is missing or damaged, get in touch with customer service, who will look into the order. In-store return and exchange rules apply to shop purchases alone, not to website orders.
Source: L'Occitane Saudi Arabia: FAQ