Can't get calls from ATT network

I have been having the same issues as I have seen in different threads about ATT numbers not being able to be come into my phone.  The T-Mobile tech folks are saying that it is on their siide and that the call is not even entering the T_mobile network.  They call and the same message that this person is  not taking calls of that there is not a vm set up. 

Has anyone gotten a resolution from this?  I even changed from my Samsung to a iPhone (they said that would fix the problem) and it didn't