Aramex: delivery limited

i had ordered a computer from EveTech on the 12/12/2019. This product was to be delivered by Aramex within 5-7 working days. I had no doubt that this product would be delivered as it was confirmed that the product was collected by Aramex. I had then phoned a few days later when i had noticed that my delivery was late. It was then that i discovered that my package was lost. Aramex took no ownership of losing my package and has now instructed me to pursue the matter with the seller, despite it being their fault. This is such poor service from a national delivery company. How can a company with sole purpose of delivering items not do the only job they have: DELIVER.