Unfortunately, I did not know about this issue and went on the website to buy a book with a coupon. I saw the quick buy option and unticked it but before I could blink the book had been charged to my credit card.
I am very angry about this
and have sent an email to kobo demanding a refund. If they don't give it to me I am going to call mastercard and tell them the payment was not authorized.
I am curious to know if this happened to anyone else, my book was not one of the free ones.