I've heard that, but once I tried to refund a game at 3 hours and got nothing but an automated response (denial) everytime I requested a refund.
In this specific case it was actually a game I played 2 hours of during a free weekend approximately 4 years before buying it, played one hour after buying it to see if it had gotten better, decided it hadn't and refunded it. But Steam counts free weekend playtime towards the refund window...
If there's any actual way to ensure a human reviews it, that'd be neat. 100% it was automatically denied by some code just checking my playtime and seeing it was past two hours.