Goodness, that's an unexpectedly large bill! Shocking when you are not expecting it, for sure. Gordon is right, we haven't launched the voice over LTE yet so that wouldn't be the culprit for what you're experiencing on you bill.
I'm happy to have it reviewed for you and reach out to discuss further. Please send your details to email@example.com to my attention.
VoLTE (voice over LTE) and HD Voice in the implementations that have launched elsewhere are counted as voice services regardless of how they are implemented. It is possible that you have used some other "voice over data" service such as Skype or Viber of similar app. Those apps use data and not voice minutes, combine that perhaps with thinking you were connected to WiFi when you were not and you could quickly exceed the included data on your plan.
Edit: Another big hint on this is "my phone bill is suppose to be $30". That would suggest a plan that includes essentially no data. If you have a smart phone that would definitely start to explain the issue. You likely need to open up the settings on the phone and find where it says data and set it to always off.