Both of the items do drop. I can personally confirm this.
You got some very bad luck over there, sadly......
The Fairy Robe I personally dropped at Captain Hookah Mission - maybe this information is helpful to you. But I know Alvida Mission map does drop it sometimes too, but I believe Hookah at a higher chance.
The Ghost Mage Robe I had a party member drop at Artis mission map - maybe it would be worth to try your luck there. I don' t think Alvida drops those.......not sure though. Lord of Knight I believe should drop this too, but like I said I saw a party member drop it at Artis mission map.
Both items are definitely in the game and do drop though, I can confirm this.
But all items of this kind do drop at a random chance (yup same with using Gada coins), so it actually might take a while till you finally get the missing part(s).
Makes me kinda sad you got so much bad luck.....I hope you now got some better luck.