The title pretty much explains my question.
No one. At the time Carthage was a oligarchic republic somewhat similar to Rome. "Head of the state" of sorts was called "Suffete"(1). However, we know about Carthage mostly from Roman sources and they had no interest in producing a detailed list of governmental officials of Carthage.
Hanno the Great (second) might have been one as he was able to prevent reinforcements being sent to Hanibal. Circa 201 BC guy named Bomilcar probably was one, as he presided Senate.
Well... no one. It was a republic in this era, not unlike the Roman one. They had their own "consuls" called Suffets and there was a senate-like body, a council of elders. I don't quite know what else to say to answer the question.