Very simple - because you can complain to us about defective articles without any problems.
Simply use our returns portal: to the returns portal
All you need is your order number and the postcode of the shipping address. (If you can't remember your order number, look here)
First, indicate that you want to "return an article". In the next step you mark the article in question. Click on "continue to reason for return". Now enter the reason for return "defective" and select "replacement item" as the refund method. If your order is not older than 6 months, you can also choose "refund to original payment method".