21 vance one's own business interests and the expense of a competitor's may not constitute a wrong¬ ful act in the context of an action for unlawful compe¬ tition. See Dun and Bradstreet (supra)at 221 C-E; Ltd & Another and compare Stellenbosch Wine Trust v. Oude Meester ( supra )at 162. See also Prok Africa ( Pty ) Ltd Group Ltd Another v NTH (Pty) Ltd & Others 1980 (3) SA 687(W) at 696. In the case of Harvey Tiling (supra), it is clear that, although there was no clear statement in the sum¬ mons to that effect, the cause of action was unfair comr petition. The first defendant, Rodomac, manufactured a tile in competition with that manufactured by the plain¬ tiff ,Harvey Tiling. The second defendant, Roux, had been......