unhappy client

I got an sms to collect a free pack of Huggies from Dischem. To my surprise when I got to the store they told me that the sms voucher expired and I no longer qualify for the free pack. I am very disappointed as I have been a loyal Huggies client throughout the year. I bought the 10 packs as per the adverti*****t and now that I need to get the free packet this is the service I get.