Here you go

I agree you have to really dive into it and most people learn by making the mistake. They could communicate it better, expecially for a ticket that is mostly issued long before it is used. So I agree with your frustration but it is in the rules and if you had asked before issuing they would have told you so.

I would suggest you take this up with OneWorld4U and see if you can't get the rules communicated better. Legally you have nothing though.