You’ll need to cancel either one of your orders as soon as possible. To do this, go to the order details page, where you’ll see the option to cancel your order under 'Can we help with anything?'
Will I be charged for cancelling my duplicate order?
If you place multiple orders by mistake, you’ll have up to five minutes to cancel the duplicate order(s) without charge. If you cancel the order after this amount of time, you may be charged an amount up to the full order value. This is because a place may have started to prepare your order or already assigned a courier to deliver it.