Can previous employers call other companies to dissuade them from hiring me?

I am a specialty pharmacist in California. I left company A, with a non compete contract (Non enforceable here in California). As I am looking for jobs in our area (Small community), Company A has been calling prospective pharmacies telling them they have no business talking to me much less hire me because I have a non compete contract in this specialty pharmacy area (compounding). This is harming my chances at earning a living. So my question is...what law are they breaking? They are telling them that I have a non complete clause (Which is technically true, but illegal in CA)..slander?? They are providing this information without even being solicited (e.g. job reference). Thanks for any help/