Slow to correct their mistakes
They sent the wrong part and have not tried to rectify this, they just forwarded my complaint to the manufacturer. They sent a drive belt for a washer or something while I ordered a pressure sensor for a washing machine, what I ordered and what I received have nothing to do with each other and because of their incompetence I am doing the dishes by hand.
Update: it has been over a month now. After my complaint Fixpart asked me to return the item so they could send me the correct one, rather than reimburse me. After about 6 weeks and an official claim I have now finally received the part I ordered.