Rentalcars.com Cancellation policy

I booked a car for pickup on the 26th of March 2021. When I went for car collection , the receptionist at Tempest Car Hire Centurion mentioned that I need to cancel it because I did not have a credit card. He did not sensitise when? Due to my busy schedule, I contacted Rentalcars.com via online chat on the 12th of April. The person said sorry you were supposed to cancel it at the reception when you collected the car. After 2 weeks, you wont be able to get your refund. I am ashamed of rentalcars.com and its directors and everyone associated with them. How can they have such a sick cancellation policy. I am going to escalate this to the highest level. My hard earned money of R 1,150.86 wont go to dustbin.