I don't think this is an issue is it? It's some time since I've done this but I think the sequence of events is you say I'm so-and-so at x000 feet on ... 1007mb. They say do something not above y000 feet on 1012mb. Unless you have a ground clearance issue you just set your altimeter and do as you are told.
My approach to life is in general do what you are told whether or not you have the strict legal right not to. They probably are doing the best thing for everybody involved so help them out... unless you have a good reason not to.
If you feel bolshy about being told what to do then simply avoid their zone.
Live and let live. Treat everyone else as professionals. Almost always they are.