I found out after sending my vehicle, a 93 miata, to a shop for a control arm replacement that it was missing the drivers side anti-sway bar link along with the hardware. After heading to a hardware store and ordering the new part I installed the new end links on both sides. Weeks later after doing an alignment for my vehicle I found out later after inspecting it due to noise that the link got removed from its bushing and was hanging lose. Again I ordered a second link and installed it. Now today after jacking up my vehicle and accidentally dropping the vehicle a little too quickly the link again got removed from its bushing and was hanging lose.

My questions are what would cause the end link to snap like this twice? did I chose the wrong hardware for it? (it is not a 100% match) did I torque it incorrectly (both times torqued to specs) or I just simply dropped the vehicle too fast, but an alignment shop would not make that mistake would they?