Voicemails being "Deposited into text"

This VM to text solution is clearly designed for Android users as it offers no advantages to iPhone users. Apparently, Android devices don't have a standard visual VM as all iOS devices do. 

Like many others on this thread, the features was suddenly enabled on my account for no apparent reason. And now, my iPhone's visual voicemail is not receiving messages at all. I continue to get text messages with non-functioning links announcing new voicemails. My only option is to dial into the T-Mobile voicemail system, enter my password, and navigate through messages using the keypad (like I'm living in 1992).

I called 611 to try to sort this out with customer support. First level support was completely unfamiliar with the iPhone and instructed me to downlaod the visual VM app. When I pointed out the app is Android only, my call was transfered to next level support. The next tech at least understood my problem, but couldn't help me correct it. I was promised a callback later in the week. That never happened. Or maybe it did and I never received the voicemail.