There are two routes. Either request the return through your account's “Order history”, after which a shipping partner gets in touch to collect it, or bring the packaged item and its invoice to a Centrepoint store anywhere in the Kingdom. Shoe Mart, Lifestyle, Babyshop and Splash products may also go back to stores of the same brand.
When an order paid through SADAD or in cash is returned online, the refund is added to your account's “My Credit” balance, while guests who paid in cash receive a return voucher. Be aware that Home Box products and Home Centre furniture ordered for scheduled delivery cannot be returned at stores.
Source: Centrepoint help center: How to return