Typically, 1-3 business days after you purchase fuel, the discounted amount will come out of your checking account. The discount you receive will depend on the program you're enrolled in. More information about the programs can be found here.
We email you a receipt outlining the transaction details which includes the discount you received. You can also view your transactions in the wallet/savings section of the app.
NOTE: The pump itself, and the receipt you receive from the pump, will not reflect the discount you receive from the Pay with GasBuddy card.