Disputing a charge which is clearly disclosed (and the carrier can demonstrate was clearly disclosed) isn't going to get OP anywhere.

In the end, this is a business model which is highly profitable and works very well. There are a vast # of people quite willing to endure silly rules to get a great price. There are others who simply won't do it.

The only way to really impact outfits such as RyanAir is for customers to vote with their feet. But, that is quite clearly not happening.