What are the legal arguments to rebut a claim of assignment of a share in a commercial entity?

The arguments include denying the claim and asserting that the assignment of shares in a commercial entity requires a written, authenticated, and registered agreement with the official authorities, in accordance with the provisions of the Companies Law, specifically Articles 161 and 162 thereof. The arguments also include challenging the validity of the evidence presented to prove the assignment, and deeming it insufficient or inconclusive.