I'm Dutch and customer service isn't always in everybody's soul... You are definitely right that some of the Klm employees are outright rude, but please realize that many people that have a bad day don't express themselves very nuanced in a non-native language.
I had several moments that I wanted to leave FB and switch to other program (and did). These decisions rarely result in better situation. Especially as you seem to have some issues with the way the program works. Making an effort to at least understand the program is essential to knowing how to use the program and get the max benifit out of it. The fact that you need to credit miles is reason for me to think this (and the fact that you don't do it yourselves..- it's quite easy actually), I only credited miles for flights 2 times in past 8yrs and these were both with air Europa in early days..
At a point I mailed flying blue, explained that I had some difficulties, explained my flying profile and they were extremely helpful by calling me and explaining how to make the system work for me! I am very happy platinum member since April this year..
In short: if you won't make the effort to understand the game, you'll never be good at playing it.