Collection is targeted for no later than 48 hours after you request it. Fridays are the exception, since DHL, their courier, doesn't operate that day, so pickup shifts to the first available day afterwards. Remote areas see the courier roughly two or three times weekly. To avoid delays, complete the return form included with your order and place it inside the parcel.
Processing takes 7 days, and the refund goes back to the method you paid with; on credit cards it may need as long as 30 days, depending on the bank. For instalment purchases, contact the instalment company about cancelling the plan or any fees that may apply.
Source: Bloomingdale's Saudi Arabia: returns