Woolworths Store Card Issues

I have a Woolworths account and for the second time today, I tried purchasing on it and it does not work in store. I transferred the cash for what I wanted to buy onto my Woolworths Account and when I got in store the card would not work. This after purchasing on the card last week. I then ended up having to pay cash again for the items. How embarrassing trying to explain and even on my App show the stoe assistant I have the credit available and show the payments I made for the items I wanted to buy. But they could do nothing. Now I am out of pocket!!!!