Free pack of nappies is a ****

If you are wasting your money and time by purchasing nappys at dischem for the 10th free please stop. After 4 months of no vouchers despite buying nappys every 2 weeks i enquired at the atrium branch . I was told i reached my 10th and a voucher will be sent a voucher , 1 week later nothing ... i purchased another pack and decided to email. The reply was im currently only on my 9th pack . How did i jump back 2 packs. This is clearly a ploy to not give the 10th free . Its so annoying as i was purchasing at a slightly higher price knowing a free pack is worth it in the end. Will definatley be taking my business elsewhere