Our wall oven shit itself two weeks before Christmas. Got a new one from good guys - oops no stock in Perth have to come from Melbourne - cupla days. You guessed it, didn't turn up until new year.
Installation agreed for about $200.00. Got home, very bad installation (off center in wall) and a bill for nearly $600.00. "Sorry mate we had to upgrade the wiring from the meter box".
Went berserk and told him what I thought. Got a phone call later from his missus saying I had reduced him to tears and he was in shock. He had never had a complaint before.
Over it - paid the bill and just got on with life.