Has anyone installed M-factory Helical LSD into there 6speed manual 335i 2007 e92 ? , Please help if so

I’m having a hard time with getting the right parts for the shop to do this job someone please help , they’re supposedly saying I’m missing the pinion ring and that mines the oem one is welded and the one I bought was supposed to come with it but ig it didn’t . I even went to MFactory with the part number they gave me and I guess it’s missing the pinion ring. the shop said they’ll call tomorrow for me and let me know everything , so now I’m stuck with my car taken apart and an lsd that’s missing a pinion ring. The shop has been cool with me but if I could have someone tell me what is it that I’m missing and link me the part so I can get the swap done would be appreciated thanks