You can cancel a payment for refueling/recharging or parking fees you made using In-car Payment, from the place where you used the service.
On the Kia Connect App, press 더보기 ▶ 인카페이먼트 ▶ 더 보기 ▶ 사용내역, select the payment item to cancel, and then cancel the payment from the place where you used the service.