The Thomann customer service is second to none.
Fast, accurate, and the most important thing at the moment: they have the money-back guarantee.
This terrible sonor bass drum leg is not for any usual drummer. Instead of normal screw+inner thread in the leg holding rossette, you got a self-tapping screw, which is not for a drummer.
To mount the rossette with that thing, you need to know the torque (Nm), the rotation speed of the scredriwer, and the most important thing: you need to hold all the components in one straight line (rossette, drum shell, screw), to avoid damages during mounting, and that is impossible at home.
Such a shame for Sonor, they just lost a very disappointed customer - if I want a do-it-yoursellf drumset, I can buy several really good parts from practically any other manufacturer.