Can I be arrested for not paying a debt in California?

No. Owing money, on its own, carries zero criminal exposure in California, there's no debtors' prison here, and a collector implying otherwise isn't describing reality.

Real trouble only starts if you've already lost in court and then blow off a subsequent order from that same court, like being ordered to appear for a judgment debtor examination, a hearing where you disclose your finances, and simply not showing up. That can lead to contempt sanctions, even a bench warrant in some cases. Look closely at what's actually being punished there, it's contempt of court, not the underlying debt, and none of it is even possible until a judgment already exists on the books.