Inaccurate vital information

I have a Vodacom data account and just in the past month I install their vodacom app.<br> It shows me my contract data plus 117.72MB prepaid balance that will expires on 31/07/2015.<br> My contract data was exhausted on the 27/07/2015 but the prepaid was their showing on the app.<br> ButI I could not for some reason use it. Upon me inquiring about it they say it was a system error but it still shows on my device. What if I was using gps and depending on their app for my connection to get me and family safe to our destination and the gps failed because I recieved false info.This big company can just say it a system error that I used up all my data but their app on my device shows I have 117.72 MB?