Millenium is not the place to be with childrens, if you have kids, you have the right for villa. Request it then.
Do not accept Millenium with kids, I was there with my newborn, nice location, nice staff, nice appartment, but not designed for a familly and not kids friendly at all!!
Accomodation department is just trying to give you this "unit" as they call it hoping that you won't open your mouth, please open it up, for your own good.
Half of Meydan is still empty so there is space here for sure...
Good luck