Maybe Thompson will warranty it? I was looking on their web site and saw an interesting blurb about their “bending fuse”. it sounds like you’ve hit the limit.
The Thomson seat post design incorporates a bending fuse to prevent catastrophic failure. All competitive seat posts we tested failed catastrophically with the seat and clamp components, and sometimes pieces of the tube and head flew off in all directions!
The Thomson seat post has a clamp, head, and upper tube strong enough to withstand 350 foot-lbs of torque. The tube will start to yield and bend at the seat tube clamp at about 250 foot-lbs of torque. Under severe impact the Thomson seat post will bend slightly and allow the rider to come to a safe stop or finish the ride.