Took my XPS13 in to a ServicePlus for battery replacement. Got an update from ServicePlus staff requesting my laptop password after they installed new battery. Didn't hear from then until I was told my laptop was ready.

Went in to pick up my laptop and was told that my SSD was unreadable and they had to re-install the system from BIOS. 

I'm a bit confused as to why they said my SSD was unreadable even after they were able to unlock my laptop???