Razer in 2018
Btw did you install Windows 10 or do anything significantly different compared to when you first got your computer? (such as changing isp and modem/router)
As a last resort thing: did you have a 4G little modem kinda thing? It could be possible to hook up your computer to that and try downloading the Synapse update via mobile internet, maybe via tethering.
I'm sure theres more intelligent and practical solutions but i havent slept yet and just wanted to pretend to be helpful while i chuckled at the Benny Hill Luria computer show.