I know dipsticks very well and have been there time and time again. Had my mondeo regased there only a few weeks ago with not a single problem as usual.

And trust me Im a fussy fucker about who touches and works on my cars. I'd be here backing you up if i'd experienced anything like the service your dad claims.

Perhaps there is a resonable explanation for what happened to your dads car, and perhaps after your dads spoken to them they could well come to an acceptable resolution - mistakes, accidents and misunderstandings do happen!

Would be interesting to hear the outcome after yours dads actually spoken to them.