Thank you all for the replies ^_^, I have some kind of update.

I contacted SE with a fresh support ticket including some of your advice (I'd report them to trading standards/should probably talk to the police about the potential forgery etc..) and that I want the item I had purchased... and by """"coincidence"""" they replied to my original ticket mere hours later. They said they finally contacted the courier and will be giving them the info they need, and will update me soon™. I guess i'll give them till next week, and if I don't hear back by then actually file the complaint/maybe seek a chargeback refund like many of you suggested (though i'm still worried about it jeopardising my SE account).