Do building codes enforce location with regard to plumbing rough-in?
There are really no code requirements to be met with respect to location other than meeting clearances and that sort of thing. For example, a toilet must be so far from walls to the side. Anything else is a matter of prerogative and your contract. 

It sounds like you have a contract dispute here, and that's off-topic on this network. If you approved a plan, and if the plumbing was installed according to plan, you'll have to fix it yourself. Otherwise, I'd expect the builder to do it.