Rentalcars.com Canceled Our Reservation For No Reason

We have made a reservation from this site. We landed at Skopje Airport 30 minutes after our scheduled arrival time due to delays at the departure airport. When we go to the car rental office, the company told us they cancelled our reservation for no reasonable reason. They said we were 30 minutes late and they just wanted to cancel! They informed us that they would refund our money from rentalcars.com when I contacted the support team for this matter and the rentalcars.com support representative said they could not get a refund of our booking fee. We couldn’t understand. We didn’t do anything wrong. Now I want to take my money back which I paid for the rental service but I couldn’t get any services.