How to get a replacement casing/tray that holds a drive within G-Raid Thunderbolt 3 RAID Array?

How can I get a replacement casing/tray/module or whatever it is called --the plastic casing that will hold an 8T drive and slide into a G-RAID 16TB 2-bay Thunderbolt 3 RAID array?? My drive was replaced under warranty, but when it was returned to me the casing was not there. Zero help after repeated tries with customer service. I cannot even find out the exact name of this tray, or the part number, or where/how to order one. Any help would be appreciated! Thanks!

UPDATE: After a ton of difficult communication, WD customer service got me the casing.