This is not true. You have the right to a "deugdelijk product" (good product) for the entire expected lifespan of the product, and if it breaks in that, they do

This is not true. You have the right to a "deugdelijk product" (good product) for the entire expected lifespan of the product, and if it breaks in that, they do have to fix it (or provide a comparable replacement). If, however, for whatever reason you don't want that, you can't demand all your money back, but only 50%. That's only if you agree to the money though, the seller can't unilaterally choose to give you 50% back instead of repairing it.