Working Holiday Visa Rules

I currently have a working holiday visa and live in Paris. I managed to find a part time job, but it doesn't pay all my living expenses. I tried to get another job to make up the difference. But, when my new employers called the gov., they said I was only allowed one job at a time on this type of visa. Is there somewhere I can confirm this? I don't recall reading this type of rule while obtaining my visa. Is there a list of rules somewhere? Or someone I can contact about this?
Any help would be great!

can you ask someone at the Direction Départementale du Travail?
I can't offer much of a help sorry..but I'd love to hear you stories on finding jobs. I am here in Paris on WHV as well. Did you have to obtain ATP yourself before searching for jobs or did your employer do that for you when you got hired?

@ randimiron This reply is late but it's true - you are only allowed to work 1 job on the working holiday permit. If you aren't making a livable wage I think one option would be to try and collect CAF.

@hansolgo Yes, You have to get your ATP yourself by lining up at the DDTE office, which if you're in Paris is only open from 9-11:30. You also don't get the ATP right way; it gets mailed to you after you provide them with:
-a photocopy of your visa
-a photocopy of your passport
-a photocopy of your job offer
-a self-addressed stamped envelope.

The ATP is then mailed to you about 1 week later (it's not a card - it's just a letter).