Log in and go to 'My eCredits' or 'Returns' and click on 'Withdraw' (option will be visible behind all 'refundable eCredits'). Click on this and within a few days the money will automatically be on the bank account/credit card/paypal that was used to pay. You will receive an email as soon as the eCredits are on the account. You can also click on 'pay' directly in this email.
You can of course also choose not to pay out the eCredits (AttitudeCoins) and to use them on your next order.