Vostro 3888 primary 2.5 in. hard-drive assembly missing

I have gone to add additional storage to my new PC to find this missing. 

https://www.dell.com/support/manuals/en-uk/vostro-3888-desktop/3888_mtcbb_sm/removing-the-primary-2.5-in.-hard-drive-assembly?guid=guid-bfbc75ff-c4cc-4254-8782-74abde39b38f&lang=en-us 

I've called numerus times and spoken to every department. Could someone please let me know how to get one!