Upvote:7
You can fly without your luggage, your luggage can fly without you if it fails to make the connection which you made, it is done often.
I guess it is a case of an airline mistake that they do not want to admit, made worse by the fact that there were two airlines involved.
It seems that you have done much already to claim compensation, and got more than you initially did, but you might be able to squeeze a bit or even a lot more out of them by going public, on twitter or some such site, or by using a consumer protection organization.
As this is a rather rare thing to happen, I think there is no standard compensation across the airlines, there might be a company standard.
If you are not happy with the compensation you got so far but not want to go public, you can write a letter, send it recorded, and ask for the proper compensation.
The more official you make the letter, the better impression you make and as far as I understand these things, the more likely your letter is taken serious.