Have u been doing any of these:
Soft resetting
Ask a friend to breed you one
Or if your in dire need of it:
Ask a friend to hack one for you.
That's what I can think of...sorry if this doesn't help you in anyway.
none but have you soft rested... though im sure you have
second piece though not my recomenbation ar or gs my friend and it worked
i i made him get it naturally he got it on his second try...
Just keep at it. Also, the fact that shinies pop up when you least expect it has been proven to be true with the majority of my shinies. So I suggest multitasking to keep your mind off things.
Also, I don't suggest cheating. It could screw up your game.