Birthday treat turns into online cheat!!

I received a gift card for my birthday. I tried to do an online purchase the day after my birthday. The system froze and a pop up said not able to process gift card please contact the help desk. I did that and got a reference no ***7. The following day I happened to be in a Shopping Centre so I thought I would pop into Woolworths because my transaction was unsuccessful. At the till I was told the gift card had no money on it. So the failed online transaction grabbed the money and left the gift card empty. I have contacted Woolworths over 5 times and all I am told is that the IT department have to resolve the issue. But 2 weeks later no progress. I am disgusted with the service.