You sure you’re connected to the VPN and then re-started Origin. You can check You are properly connected by checking the Store in Origin and looking at the countdown timer, it should be 1 day something.
Then go to Your games and hover over BF4 and it should give You the option to pre-load.
My preload is all done , In theory We can connect to a Korean VPN and be playing by tomorrow, but I don’t know if any Europe or US server are up yet.