Telkom is *****ing from clients for sure

Hi guys, I’m experiencing a problem with Telkom, I’m using 10gig day and 10gig night WiFi router telkom, it’s a second month as of May , I noticed data is depleted within three days of use, I’m not much into internet, so far for May months I definitely sure used the data for two emails and WhatsApp. I called telkom and I’m told I did use that data, I tried explain to them that I’ve been using this work wifi router for more than two years now and this is the 1st experience I had that 10gig data is depleted within three days or nights. I haven’t increased my use of internet, I didn’t get help I deserve instead I felt I had to accept that I used 20gig in three days and it’s depleted, no ways and that is so impossible. Telkom is not even prepared to look into the matter, basically they told I can go to ICASA, and I will go but guys be warned with telkom