My question involves labor and employment law for the state of: CA

Sorry for the title - in a nutshell, i resigned over the phone from a retail job two months ago, then, just recently found a new office job. Two days ago, new job rescinded the job because ex-employer told the new job that i had not resigned, but had instead been fired for having "a poor attitude and not showing up to work" !!

What can i do about this ? Is there anything i can even do about this ? Please help ?