I never said that TransformCo purchased the entirety of Sears.
It is obvious from what I posted that TransformCo did not purchase the entirety of Sears. But it stands to reason that if OP is receiving correspondences saying they owe the signing bonus that TransformCo purchased the portion of Sears that OP worked for.
You don't have any more info than I have on what TransformCo purchased. But if that part of Sears that was purchased has the contract with OP, then they owe the signing contract.

