Lisa,

Whether the tech working on your car was corrupt enough to steal the lugnuts or careless enough to misplace them, I’d bet he/she also got sloppy with the air gun. I’d check the torque on all 20 lug nuts by hand – not with an air gun ASAP. Otherwise you’ll be shopping for new brake rotors very soon.

Re. The missing nuts – if you paid for the work with a credit card and they don’t return the chrome lugs or pay for them, I would withhold payment and send a letter to the credit card company explaining the situation (with a cc to the shop). Consumer protection laws in most states give you the right to withhold payment in a dispute with a merchant interest free.

Hope this helps.