The ad, in a leaflet mailed to customers along with monthly phone accounts, was titled: "Do THE BROADEST BAND from R199 pm".
Though the ad offered up to 30 gigabytes local usage free, a small-print disclaimer said free local usage applied only "once the original internet account has reached its limit".
The ASA said advertisers could not rely on a disclaimer to clear a misleading impression created in the main body of an ad.
It also said the "broadest band" claim was misleading as the R199 "from" price related to a 384kpbs line, which was not the "broadest" band available.
The ASA ordered that the ad be withdrawn.
- Sapa