Seems like the shop failed to recognize it was not installed correctly.
Many shops do not allow customers to bring their own parts for this very reason.

Using old parts of an assembly requires some inspection of those parts to make sure they are still good and fit right, etc. You do not always need new parts in an assembly, I just like to do it because that CO assembly will run 100kmi or more, my OEM's are 225kmi currently.

What/where/who/when was the breakdown that led to failure will be between you and the shop.

 

There should be a washer below that bottom rubber pillow. I am willing to bet they left it off when assembling the strut. I have done this before on a previous car.... looked exactly like that picture in the first post.

On the strut, the order is: flat washer, pillow, hat, pillow, U-washer, nut... then the adjuster for the ride mode (electronic module that goes on top). That sleeve goes in between the washers with the pillows on it....

 

Thanks for everyone’s feedback, I have already ordered the KYB strut mount kit with all the parts needed to make sure nothing is missing...
Should be in on Wed-Thursday (fastest I could find it was Amazon, not stocked at any auto parts store and all of them stated “extended processing time”) and I will update when I find out if it was missing that piece...

 

Finally got all of the parts in and my mechanic took both side back apart and they left of the little piece that keeps it from pushing though the strut mount.
Once realizing they were at fault, they refunded the entire job before I could even ask them about covering my extra parts/etc.
Thanks everyone for the diagram, part numbers, and input, we were all stumped for a few days on what it could be...