Telkom mobile

Hi please help, I am not happy with telkom mobile ,I have wifi router with limited data bundles, now I have received statement shows that I exceeded my limit I'm charged R1900 which is to be debited from my account I also confirmed telephonically with them they mentioned dates that we were not at home we were on holiday, no one was home on that dates ,they failed to provide me with proof for that particular day they are referring to.