Support regarding refunds and other related issues can be found in Steam's support menu.
Select "SUPPORT" at the Steam website and check for World League Baseball in your "RECENT PRODUCTS" list or through the "Purchases" menu. There, you can learn more about refunds.
Please note that refunds must be conducted within two weeks from the date of purchase and your total playtime must be within 2 hours according to Steam policies.
World League Baseball