3 for 2 black Friday rip-off

The 3 for 2 deals as a build up for black Friday is a ****. Woolworths doesn't ring-fence this promo by brand or by shelf/stand/rack where this promo is applicable at checkout/payment stage. What really happens is that if you are buying 9 items as an example; if you take 3 same brand/items on the same rack that are R500 each as an example, and take another 3 items from same brand/rack with a price for R100 each and another 3 items from same brand/rack for R20 each; Woolworths checkout points are programmed to give R60 discount with the example I have given above, i.e (20 X 3) instead of R620 discount (500 + 100 + 20). I believe a lot of people have fell on this trap in the name of black Friday 3 for 2 deals. To beat their trap you need to split those 9 items into 3 separate transactions to be able to get the R620 saving/discount. This is very naughty if not **********. Can DisChem and Clicks assist Woolworths programmers to do the right thing if they are not doing ***** as these other two retailers run the 3 for 2 deals regularly and correctly.