Help! Get compett tires without accessories

Hello to Allen suchen Rat, habe mir 1 week ago 4 complete tires ordered, however no accessories received. The local tyre dealer and also a mechanic explained to me that they can not mount the rims, because ‘rings’, which have to be mounted on the inside of the rims, and the right screws are missing. The seller (reifendirekt.de / gommediretta.it) tells me today he did not have these parts at all, could not order them at all and I would have to buy those where otherwise. He tells me that he can’t order me the accessories and he doesn’t know where to get something special, because the rings have to be exactly for the rims and my car model. Now my question: can the seller do something like that, I had exactly specified my car model when ordering (invoice in annex) maturedirectly doesn’t want to know much about a return, communication with them is very bad, partly no answer and contradictory indication en (must unfortunately turn to the Italian support there from South Tyrol) Rims: DOTZ Tupac 8.00 x 18 (LK 5/120, ET 35) Car: BMW 320D Touring 390L 120kW 1995ccm, diesel Thanks for any help andreas