Not receiving new voicemail notificationsI had

I stopped receiving new voicemail notifications a couple of months ago when I noticed that I had not received any voicemail. When I dialed "1" to get into my voicemail, I was surprised that I had numerous new voicemails. I called Tmobile, was ont he phone with tmobile support ofr over an hour and got no where. They had me do all kinds of trouble shooting and checking settings. They said I needed to contact Apple. I made an appointment with the Apple Store. They checked all the setting which are correct and told me they didn't think its a phone issue.They did get it working for a few days. I was receiving new voicemail notifications but they were hours delayed.

I went to a local T Mobile store, upgraded my phone to the 10 Pro Max. I explained my issue. They said I needed to call T Mobile support. This time ask for a higher level tech support for voicemail. The tech support person spent over an hour with me, again, trouble shooting. Got nowhere. She said she has to open a ticket to have the isuue worked on.  It has been over three weeks and I have not heard anything. 

Today I called Tmobile to follow up and the person I talked to said all she can see in the notes in my account is that a ticket was opened. No other updates. She wanted to start trouble shooting. I stopped her and explained that I've already been through this numerous times and I want this resolved. I asked to speak to someone who cna help me. She was going to put me through her supervisor who she said will only tell me what she already told me. I lost it and hung up. Help!!!!!