No help from Vodacom

I got 5 Gigs data for the first month of my contract. Sunday I have only used a total of around 1.5 gigs and I had R62 on my phone. I was busy on my phone when my internet went off monday morning When I checked my data and airtime later everything was on 0. Where did my data and airtime go. I phoned the 135 number over 20 times in the past 3 days and everytime it says I must call back because the lines are very busy. I have requested about 8 call backs on the website in the past two days. I got only one call back this morning, but there was no sound. I requested again for a call back but got none. I wish I could say I had bad service but I had NO service. I would give 0 stars if possible.