I have my voicemail set up.
I just checked my menu and my DND isn't set up.
Ok, great. So if you call your PM number now, does it go to voicemail, or do you still get immediately dropped after the 3 tones?
If it's still the 3 tones, then my suspicion would be a provisioning issue... since you're already in queue with the mods, they may have to take over with a resolution to this since it's beyond anything we can do.
The results of your testing the SIM card in another phone may shed a bit more light or further reaffirm conclusions here.