It never harms to write a letter expressing your feelings, but don't make it seem like you're out to get money out of them, because no one likes to feel that people are out to get money out of them, and in general the CAA are probably not the best people to make enemies from.
What you should do if you haven't done so already, though, is write to the person who received your license and was kind enough to contact you to clear the matter up. He certainly didn't need to do that, and thanking him is probably a far more productive thing to do than moaning. Making friends is always better than making enemies, and the amount of money you might be able to get is pretty insignificant in the grand scheme of things.
FFF
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