Ok, there are 2 SDS options, all phone systems came with SDS as standard, so you have just got that version.
You could also order SDS for the whole of the Infotainment system and in this case you can control the whole of the radio/nav etc. But it was an option before you go back shouting at Audi.
When the RNS-E is equipped with SDS then the mic is rerouted through the RNS-E and then onto the phone kit.
It is possible to hack your RNS-E (navigation) for SDS with an update disk, but you still need to do the mic rerouting.
I did an A3 on friday, took about an hour to reroute the mic and hack the Nav, but if you update a year later to a new disk you will lose the SDS hack, so you must apply the hack again.