Still thinking they're trying to fob you off mate. I've had my axles, release bearing, squeeky clutch pedal and a couple of minor other bits done there. They seem pretty happy in carrying out warranty work mate, might be worth a drive up there (if you need directions PM me), but book it in cos they'll need to check it out first and get Nissan go ahead, which they always seem to have done within a day for me
As far as the girls go - the one in the middle is my missus. They did a very poor job though and got the car covered in baby oil too, so I had bum & leg prints all over the doors and bonnet. Obviously I didn't wash em off for over 2 weeks tho - brilliant