All the stories I've heard about that came from people with bad insurance (for instance: insurance programs that could rescind coverage if you were diagnosed with something serious, and that functioned mostly as billing processors for routine care, which is where ~none of the expense in the system is). The ACA did effectively regulate those plans out of existence, so if you had one, and relied on it, it raised your cost.

But when we talk about the ACA's impact on cost, we're always talking in a macro sense. Every program has individual winners and losers.