If your really want a c/s becuase thats something you want for you, then push for it or change to another OB.

I wouldnt just go on your mums and your sisters births though, becuase you could have an entirely differnt one. Positioning as mentioned, has a lot to do with it, both yours and the babys.

If you want to, get another opinion for a different OB and/or chiro.
Many OBs may not want to go in to major abdominal surgery if they think its avoidable, but hes not about to put you or your baby at risk either.