second by attempting to short change me on the compensation.
Did they provide you with the EU leaflet on your rights on compensation for delays, denied boarding etc? If they did and you still accepted €250 then I'm not sure you'll get very far. Some major airlines will often offer free tickets to pax instead of having to pay out the €600. If you accept the airlines "offer", after being presented all the facts, than that's up to you.
If they did not give you the leaflet, then you have a very good case for complaint!