Also, to the OP, fraud requires a deliberate measure of intent on their part to prejudice against you for their own gain or to cause you loss. If you feel that they have deliberately denied you this gluten-free meal specifically to save them...some...cash (I thought this was a subsidised airline, pfft
) or to injure you in some way, then you would clearly have a case to sue to recover your costs in court or alert prosecutors for any criminal actions.
If they can show it was a mistake and they tried to remedy it, or that they provided everything they contracted to do in their contract of carriage with you and you simply refused to accept things, well, that is a different matter.
If we want to continue to throw about loose language and hypotheticals, accusing a company of fraud so vociferously and repeatedly, in a public forum, could be considered defamatory...especially where in France these things are not looked too kindly upon...
http://www.bbc.co.uk/news/technology-28331598