It should show up in less than 48 hours. How did you order it, online or over the phone? If online, did you get a confirmation email and can you see it as one of your subscribed channels when you log into your My TELUS account?
The other thing that it could be is related to a known issue that the development team is working on resolving. Some channels that aren't available away from your home internet (including MSNBC) aren't showing up correctly in the default guide view. You can either set your guide view to 'my subscribed channels' (top left icon of the guide screen - it looks like 3 horizontal sliders) or you can try to access MSNBC from the Pik TV home screen 'On Now' row and scrolling right until you see MSNBC. There is a discussion about this issue here: https://forum.telus.com/t5/Pik-TV/Subscribed-channel-not-showing-in-Guide/td-p/113449