This is trivial to solve.

Launch two parallel cases. One against Meta top execs for criminal behavior, the other one as antitrust against Meta for abusing their market position. Two cases at once gives you negotiating power and clearly signals that you're serious about curtailing their influence.

Ideally this results in jail time for Meta execs, but at a minimum divesting them of Whatsapp should be achievable. By the end you should be able to get Meta's businesses operating independently under new leadership.