disappearing airtime & data

Called vodacom because my data and airtime disappeared.

The consultant was rude and shouting at me . I was told I went on the internet... when I told her I wasn't on the internet she starts shouting telling me to check on my phone what I used the data for. I didn't know 100mb + airtime can disappear so quickly just from using whatsapp, unless I'm wrong. My automatic updates are off , I don't use social media sites like facebook. I only have whatsapp... this is the first time I'm using the sim in about 2 weeks.

ref : ********** 442, consultant: Mathapelo Modiga