The fare for 1st in 1 leg and business for the other is almost certainly the same as 1st throughout. The only way to force the airline to give a fare reduction would have been to go business the whole way on that one way journey. As it stands, all they are required to do ( I believe ) is provide a fare difference if there is one

It's not a pretence , it just is; is it nice... no... given that they don't *have* to give anything, you could try writing in and seeing if they will give something ex gratia

If Emirates doesn't meet your needs, then indeed should go to another airline but may find the same there