Welcome to the Bunnings Workshop community @het. It's fantastic to have you join us, and many thanks for your question about your pendant light.
Unless there is a D.I.Y. way of shortening the lead inside the top housing, this is a job for an electrician as the lead will need to be cut, shortened and re-wired. I strongly suggest you employ the services of a qualified professional instead of attempting a fix yourself. You could fold some of the cord over at the top and fix the folded section with a cable tie as a temporary solution. That would raise it for you but wouldn't exactly be aesthetically pleasing. I'll include an image below to illustrate.