"Prefixes cannot be changed"+scour turning my item magic

I was crafting a physical foil, got merciless+2 bad suffixes so I went to lock prefixes and scour with the intent of multimodding, and then got a magic item after scouring. I tried again and it happened again. So now i'm 4 ex poorer and still don't have a sword.

https://i.imgur.com/AEXSueQ.jpg

https://i.imgur.com/FAwlDyP.jpg