C-Section "Flap"

I have a ...."flap" for a lack of a better term...of skin over my multiple c-section scars. After my first child, I did all sorts of core work outs to try to maybe tighten my muscles and skin (is it even possible?) and it seemed to make it a little less flappy... but it was definitely still a flap! 5 years later, it was still there. And I had another child with a c-section so I have to start again from square 1.
Is that all there really is to do and I just need to be patient for more than 5 years? Is it possible for me to ever have a flat stomach again? (I don't plan on having more kids :D)