I have an Aeropost that got stuck after I used my 2014 Giant Defy Advanced Carbon Fibre bike to commute (bike had to be stored in a cage outside during workday... in Canada therefore Fall temp btwn 1-10 degress).
The seat post is an Aero (tear drop shape) in a carbon frame.
Had been stuck for three years, but with a combination of Carbomove AND using this reversible clamp as a spread I was able to finally remove the seat post.
Technique involved spraying with Carbomove for a few days then, when the clamp arrived, using it as a spreader from the bottom bracket to the front of the seatpost... After a handful of squeezes on the clamp to apply outward pressure, the seat post popped out.
I called 15 otherwise really reputable bike shops and they all said it would be over $100 and may not get it out anyway. Oh and it may break your frame and almost certainly will ruin your seatpost...
Hope this helps others in the same spot.