Hi:
Before you return it, see if this works...
Since your notebook is running in S mode, you can't run any apps that aren't from the Windows store including driver exe files and whatnot.
So...we are going to have to try some creative driver installing here...
Get a USB flash drive, download and unzip the latest Realtek 8821CE wifi driver from my Skydrive folder at the link below.
https://1drv.ms/u/s!ApMb5dJXSS-Dggen6t_Lt2eggvfZ?e=lAgiIl
You want the file labeled sp107515.zip
What I have done is to extract the raw drivers from the exe file, so you can manually install them.
Copy the file folder you unzipped to your flash drive, plug the flash drive into your new notebook and copy the folder somewhere that you can browse to such as your downloads or documents folder.
After you do that, go to the device manager, right click on the problematic RTL8821CE wifi adapter.
Select Uninstall and check the uninstall driver box.
Restart the PC and the device should reinstall itself.
Now click on the RTL8821CE wifi adapter. Click on the driver tab. Click on Update driver.
Select the Browse my computer for driver software option and browse to the driver folder you copied and pasted to your notebook.
Make sure the Include subfolders box is checked and the driver should install.
Then see if you can connect to the internet.
If that doesn't work I would return the notebook since they should take it back.