iphone voicemail greeting

Update for y'all. After another round with support I told them that I was going to cancel my service with T-Mobile. I was a Sprint customer and never actually "chose" TMobile anyway. I let them know this on the standard post-support survey. Woke up this morning and my voicemail was working. No idea why. If I had known threatening to leave would have solved the problem, i would have done this months ago! 😀 I do know that this issue had nothing to do with the phone itself but other than that no idea. My hunch is that it did have something to do with the iOS update, but then again my family all have the same service, same phone, all former Sprint customers from long ago, and they had no problems at all….Thank you folks for the suggestions and I hope your issues get to some sort of resolution faster than mine did!