https://sheldonbrown.com/stuck-seatposts.html
The key is to get the seatpost rotating.
Given what you have there you might try this approach -
1) Replace the seat and micro adjust top back into the seatpost tube.
2) Drill two holes in the top of the seatpost and through the stub end of the micro adjust assembly.
3) Remove the micro adjust and seat, then slather in JBWeld. Replace, then secure with two bolts and nuts through the holes you drilled in step 2. Allow the epoxy to cure.
4) Remove the seatpost binder bolt; set aside. Pry open the wings of the seatpost clamp (gently), using a flat screwdriver.
5) Apply penetrating oil (Kroil, PB Blaster, etc) between the seatpost and the seat tube. Do this repeatedly, until you are certain that the lubricant is getting between seatpost and seat tube. (Might take repeated applications over a period of hours. Time is your friend.)
6) After the soaking is done, lightly pry apart the seatpost clamp wings again.
7) Set the bike up so that you can easily apply twisting leverage to the seat. Try rotating the seat back and forth. If the penetrant has been effective you should hear or feel a pop, and the seatpost should begin to turn.
8) If the seatpost still won't turn, try using vinegar with a little dish soap as a penetrant. Apply as you did for the penetrating oil and let sit for hours. Repeat step 7.
If the above methods are unsuccessful, you might need to visit your local machine shop to have them take the aluminum out on a drill press.
Pry-out may be an option if you have mad fabrication skills -