Very sorry to hear that you are still awaiting delivery of your order. Delivery estimates, along with service delays (usually due to new product launches/high order volumes) can be found on our delivery information page
Slightly delayed mail is fairly common, lost items however are very rare. Please note that Royal Mail will not class an item as lost in transit until a certain number of working days after the shipping date have passed. (UK - 15 Working Days, EU - 20 Working Days, Rest of World - 25 Working Days).
Please only open up a ticket if your order is still not with you after this time has passed, as this is when we can take the most appropriate action.
If you have not yet received a shipping update for your order, please see our "Has my order shipped yet" article