Dstv false advertising

Dstv internet they are advertising false information for their promotional internet packages, I am using Dstv compacts which i was paying R429 for it and in their advert they promised that if you take the additional internet package it will cost R70 which makes R499 per month but now they charging me R548 for the past 4 months i have been phoning them since the 1st month and they promised to fix it until now they didn't.