Thank you all for your replies, although none address what my issue is with KLM. I am saying their booking process is deceiving to someone who doesn't travel regularly. I have tried replicating what my sister did and I see exactly how she got tricked into paying 40 euros to hold a flight for 24hrs instead of just paying for it knowing she had 24hrs to cancel for a full refund.

On the page before getting in to passenger details you see this:



That is literally telling you to PAY 20 euros (her 40 euros was for two passengers) to hold a flight for 24hrs. They are offering no special LONGER hold, or no other benefits either than "here, pay us 20 euros a person to hold something we are already holding for free".

So at this point it is already very deceiving.

But it gets worse, if you go into "View trip details and ticket conditions" on that same page you see this:



So again, my concern is with sneaky deceptions. KLM does not show anywhere on the booking process that there is any option other than paying this "fee" if you want the option of cancelling a flight you booked in under 24hrs. And again, this applies to someone who doesnt travel regularly. Everyone's replies to my thread are correct, of course it should be obvious, of course KLM honors the 24hr cancellation window... BUT, if you dont travel as much as we all do here, you wouldnt know this. You would get to this page after searching for the flight you wanted, and you'd see a big prominent box before clicking the "next" screen that says PAY US MONEY IF YOU WANT TO BE ABLE TO CANCEL THIS FLIGHT IN THE NEXT 24HRS.

And for context here is what you get before payment screen when you book a flight on united.com:


And here is what you get on aa.com


These arent hidden in links, or deep in faq's, they are prominently visible on the SAME page where you are making payment.

KLM on the other hand hides any clear message and prominently stresses a 20 euro option to PAY for something that is FREE. It is sneaky and it is a blatant deception.