Useless

I am paying my account every time in full. Last month, Vodacom cut my line of because they say I owed them R36.00 according to them, when the full amount was paid. I paid the R36,00 and the line was open again. Now this month I paid the full amount of R2973,47. Just this week I received an e-mail saying the account is outstanding with R500,00. Vodacom send me the statement and it shows that the Balance on the 9th of June 2015 is R0,00<br> <br> What the hell is going on????