if he is any sort of decent mechanic, he would have fitted the correct bushes and fitted them correctly. if he hasn't done this then tell him to get it sorted out free of charge because it's his failing.
i am assuming you didn't give him the bushes to fit?
is he a proper garage? if he is the trading std bods would take a dim view of dangerous repairs being done.as if the tyres are new and are wearing already the car must be dangerous to drive as the tyres are not in their optimum position.
if you are a girl take your b/f, hubby or a bloke you know to be able to hard nose it with him.