Nametags not naming, and then takes away nametag thinking its used

I had tamed a horse (as one does!) and i went to name it after putting armour on it and saddle i went to get my nametags (i have five) i used one and it didnt name it and it took the nametag away, it was infuriating, so i tried again and it didnt name it and it took away my nametag, at that point i gave up not wanting to loose nametags that will take hours to find again