Broken off Lug nuts tire studs

The original mechanic when it happened the first time said the same thing. That they used the high powered torque wrench and over tightened the lugs nuts. the problem I am running into is this store which I shall just come out and say is WMART is claiming that there is no way they could have over torqued it because their “system” won’t allow it to torque past the listed specifications. They put it into their “system” and it won’t allow them to go past the “recommended” specifications.

And for the record, no I"m not real excited that I even bought tires at WMart but the fact of the matter is when you live in the middle of no where you go where ever you are going to get ripped off and WMart was our only option. The only reason we returned to have them put on this latest tire is that we thought the tires were still under warranty when one of them burst.