I am trying to return my O2 Hotspot device and my contract was terminated by Telefonica in December 2019 and since then i am following with O2 Store from where i have this device obtained as well as Hotline numbers at customer support and different personnel connected by Customer Service. I was assured every time i had spoken they wills send me the email to return the device but never received. Its mental harassment to me. Let me know how i can. return the device. 

I have tried to long in to Longin center but failed, have followed #twitter @o2de 

Edit by o2_Katja: Verschoben zu Englisch und Screens bearbeitet (sorry, dabei ist ein Bild verloren gegangen wie ich gerade sehe)