GMS Worldwide Express — my shipment not received

My docket no[[protected]] still not delivered to me even if it was out for delivery on 26th nov 2018, as per the tracking details. Unfortunately tracking item shows "out for delivery" while the courier boy did not reached at delivery address. When i call them and ask about delivery, they are telling that they are not responsible for that. I don't know when will i receive my material.. As i need the docked urgently, need your kind intervention in the matter...