Straight from the site:
What can I request a refund for? Valve will, upon request via help.steampowered.com, issue a refund for any title that is requested within 14 days of purchase and has been played for less than 2 hours (this includes online, offline and shared library playtime). Even if you fall outside of the refund rules we’ve described, you can submit a request and we’ll take a look at it.
Looks pretty clear to me, you had plenty time to refund it.
I mean, I don’t want to need an active Internet connection to play a single player game.
Being forced to become dependent on a external party for a single player game is stupid and dishonest. What happens if their verification servers goes down?
At least, I assume that it needs an active Internet connection to check if your logged in or not.
Well that’s understandable on their part. If people are too lazy/unable to learn how to fix something they better pay someone to do it for them before they fuck their whole system.
But this is nothing new even for windows, so bit of a weird take in my opinion.