Modern day ******s

How for the life of me I cannot seem to understand why my electricity balance went from 11 May PEC - R214.08 Utility Balance R33.78 to 13 May PEC - Less Than Min Level, Current Balance R164.08. Then again 15 May PEC - Wallet - Less Than Min Level, Current Balance R114.08 to 18 May PEC - Wallet - Less Than Min Level, Current Balance R64.08 Maximum 3 days your electricity drops like this... And to top it off I'm never home because I work 12 hour shifts. And when I do get home all I do is literally have a shower. Can someone please explain this to me ???? And this ain't the first time... It's been happening for the past year!!!