10 Gig instead of 80 gig deal

My mother took out the 80 gig contract with Telkom mobile from Bloemfontein. They have not given her the 40 gig night and 40 gig day data as per advertised deal but have been giving her 10gigs instead. We have tried to call Telkom mobile customer care line that is never answered and it seems it is just a ploy to avoid customers. She travelled almost 400km from QwaQwa to Bloemfontein to complain and demand answers as there is never any statement issued and there is no answer on their customer call centre to lodge a complaint. When they said the 10 gig was a technical error that needs to be corrected by their head office technicians. She is till to now to receive any assistance or feedback regarding the over bill that they can not give her statements for and they keep deducting huge amount from her account without resolving their issue with the 80 gig.