My advice with anything Public Mobile is to take the 10 or 15 minutes to run into your local Walmart or whichever retail store sells Public Mobile service, they know exactly what their doing and can fix you right back up to your autopay, easy peasy
Any problems I have ever had with Public Mobile, which is actually few and far between, I go to my local Walmart or wherever you can purchase Public Mobile minutes, and they are always very helpful and I end up having to do nothing