I've just made sure my mother and her family got their €600 compensation each from MH for delay due to technical reasons. Make sure you write a letter to KLM yourself and also use the latest ruling were the European Supreme Court ruled that technical faults do not count towards extraordinary circumstances.

You can PM me if you want the letter I wrote.

Airlines almost always try to refuse based on the first letter. It's just math to how many people will actually try a second time to get their money. You can also use EUClaim or any other site, but basically to take up a large portion of the money are you entitled to by law!

I always send out letters, complaint or compliment. It doesn't take me much time and for the past years have had many succeses, but you have to me persistent!