Legal Question in Employment Law in California

Unless it's something you caused, it sounds like they should be on the hook for the air fare, at least. It would be honorable for them to pony up the cash to reimburse you.

Then again, all employment in California is presumed to be at will unless otherwise agreed in an employment contract, etc. I guess you may have an argument for promissory estoppel (you reasonably relied on their promise to your detriment and sustained damages as a result), but is it really with your time for $241??

Just send them a letter and ask them to reimburse you. If they will not agree, just drop it. It makes them look bad and what they did is wrong.