My family and I moved out of an appartment in Menton recently and the landlord is not paying our deposit back and trying to claim more. Does anyone know what we can do or know anyone that can help.

Thanks

You could always hire a lawyer who is prepared to speak English but you might just as well use this forum for that sort of advice because the lawyer is unlikely to take it further (or you would be unlikely to want to at the additional cost).
This is an age old problem often asked on this form. Many French tenants avoid the problem by not paying their last 2 months rent against the never-to-be-returned deposit. This is actually illegal but the landlord can do little about it because as in your case, legal recourse is not worth it. You in good faith have paid up to the end and now you are getting the other end of the stick.
Without going directly to court, the answer is that the competent authority to settle such a dispute is the "Commission de Conciliation" which is very approachable and free but you will have to address them in French. Maybe a friend could help translate for you.