The non-existent free bags at Woolworths

Last week I received a voucher from Woolworths offering me a reusable shopping bag with my next purchase. On the 10th of Feb I went to Woolworths Verdi without a bag, thinking I am going to claim my free bag. I was not surprised at all when I was told they haven't got the bags. I have become so used to Woolworths offering customers rewards, deals, specials that do not exist! I complained to customer services and was told the bags are available at "selected" stores. I wrote back to customer services and asked them to let me have a list of these selected stores. I do not expect to hear from them. Yesterday I went to Cresta, taking two bags with me even though I knew I would need three bags, and once again I was told the free reusable bags do not exist. (And Cresta is probably the biggest store in Gauteng). Once again I was told I can pay R6 something for a plastic bag. So even though Woolworths have been bragging about the fact that they are reducing the use of plastic, they now want us to buy the plastic bags. Just like with their offers of buy two and get 20% off, which most of the time is NOT the case when you arrive at the checkout point, these bags do not exist! I have not bought a plastic bag from a supermarket in five years, why must I now buy them from Woolworths?