Cool and Calm

This is free tax advise that I recently gave to a young, headstrong friend.

When you receive a tax bill with which you disagree, immediately pay that tax in full.
Then begin a letter war with the taxing agency, coolly demanding a refund of your tax payment, calmly explaining why you feel the tax was unjustified. Make no recriminations, make no threats even if threatened.
From your innocent position of having been robbed by the government, it is easier to demand that they refund your payment to you, and they cannot jail you or attach nonpayment penalties. Prompt payment surprises the government, puts them on their back foot.
This is the strategy that I used when the government demanded taxes that I did not even know existed, I promptly paid it, and then after an eight month letter campaign I got my refund in full from the government. Which was pleasant.