Very poor service

On 19th of November I ordered a motorcycle GPS bundle from ebucks. My order number is ***1. GPS bundle supposed to include 4 items: GPS, car fitting, carrying case and anti theft. Few days later we received only one item, the GPS. After a full week of constant fighting and a number of reference numbers we eventually had another delivery. This time 2 items were delivered. Carrying case is still outstanding. I can understand that first delivery could be an honest mistake but how to explain that item is still missing even after second delivery?