Giant aero seat post alternative

Unfortunately I snapped the seat post on my Giant TCR this morning after hitting a pothole. I’m surprised it snapped as there was no sign of a weakness. Rather annoying as I had to ride 10 miles home out of the saddle, my legs were on fire by the time I got back.
It looks like the carbon aero Vector seat post is specific to the frame unless somebody knows of an alternative. A replacement from the local Giant dealer is around £100-120.
I’m also keen to see if I can make a damage claim from the council as the pothole was right across the road with no way of avoiding it. Hit it at about 20mph and snap, off came the saddle.