Hey guys, I have a bike problem. Can y'all help me out?

On the MTB I use shimmy SPD cleats/pedals. The cleat on my right foot keeps getting rotated heel out. I line it up correctly, and tighten the bolts so tight there are freaking sparks, but after a few rides it's rotated out again, and now I'm getting some pain across the top of that due to this.

What do?