Poor delivery service

I run a photographic business from home. A crucial computer part I needed was shipped via Dawn Wing. Collected from the supplier on Wednesday morning around 10 AM. I was assured that I should receive the package by Thursday, 02 April 2015. The package left Dawn Wing's depot at 07h21 on the 2nd April. During calls I made to Dawn Wing on Thursday morning I was assured that the package would be delivered after 13h00 that same day. Subsequent calls at 15h00 and 15h45 and a call back at 16h00 indicated that the delivery was late due to traffic and that I could expect it around 18h00.....which was still sort of acceptable. Nothing was delivered. During a phone call to their office on Friday morning they tried to blame a 3rd party which they could not get hold of.. I have no agreements or anything to do with any 3rd party, Dawn Wing was paid and used as the courier to deliver the package, any excuses are feeble excuses. The service is in stark contrast to their voice answered phone service. Tracking #***