Fedex — Delay in UK delivery

We have dispatched shipment to UK in 8th July & shipment has been reached to UK on 11th July but it has been around a week but customer didn't get his delivery yet. I wonder what's problem with you guys? Neither you're delivering shipment nor explaining what's wrong with this? There are life saving cancer medicine in the shipment which is waiting patient to eat. This is ridiculous how can you play with someone's Life? He keeps calling your FedEx UK post for delivery but you don't have any exact update. When you're going to deliver it? Due to this concern he'll never use FedEx shipping again.