I just read your message and feel really concerned about what you are talking about.
You are totally right, a ot of young people work in firms as interns and are payed 300 euros. That is not much! I experienced it myself 3 years ago. Actually I experienced 3 internships, payed and unpayed.
The french governement is preparing a law in order to make interns payed a little more, because some firms make a lot of benefits as they pay interns that price.
You are also totally right, the french ambassy can offer assistance with obtaining a convention de stage. But you still have to find an employer.
Maybe I can help you finding an employer? Just tell me what kind of internship you would like (Marketing, finance...?), what area (Paris, South of France...), and tell me if you speak a little french. You an also send me your CV and resume if you want an advice about them from a french point of view, or ask me questions about what you would like to know.
I am actually creating a free website dedicated to internships in france (www.stage-en-france.com
) to help people like you find an internship or a job.
So do not hesitate to contact me, I would be glad to help you.