Zero professionalism, I made a purchase arrives qu...

Zero professionalism, I made a purchase arrives quickly but without an invoice ... I asked for assistance to change it but nothing they answer me to look on the site where nn there are the data I need to evaluate a change ... I mobilize for the return x buy elsewhere, I am asked for another 40 euros x the costs will be collected after 2 weeks! And the refund ??? A month and still nothing! They have the goods 150 euros paid + 40 expenses ... the worst supplier I have ever tried ...