Collect-a-Can has been conducting an expensive PR campaign for more than a decade. This alone should make you wonder! The motivation is to counter negative perceptions which might be generated by the following fact:
It is far more economical to recycle aluminium cans than steel cans.
Using recycled aluminium saves 95% of the energy cost compared to primary production. For steel, only 33% is saved. (And that's only if it hasn't rusted).

Free of the carbon dioxide taxes applied in other countries, South African companies, mainly SAB, continue to use steel cans, because they are fractionally cheaper. Iscor produces the steel, and Nampak makes the cans.
By the way, the cost of this ad appearing just once in a national newspaper, is equivalent to the material cost increase to produce over 300 000 340ml cans from aluminium instead of steel.