Turn on shamu's AT&T HD Voice

Ok, I got the Samsung Gear S2 watch which runs on 4g today thinking the Nexus 6 at least had HD Voice because the 5 did and you have to have it to connect to A&T's NumberSync or it wont work on 4g and its useless. Anyway, I got everything to work except I couldn't get it to connect to the NumberSync with the error "We are sorry. We cannot set up NumberSync because your device does not have HD Voice...." I called AT&T and they asked for my IMEI number and that will tell them and they said it must not have HD Voice. Is there some way I can get this enabled on this phone so I can use this?

Thanks!