Terrible online shopping experience

I placed an online order on the 06/05 order #o*** and obviously the items were in stock else I wouldn't have been able to add them to my cart. I was well aware of the delivery date being the 27/05 but just a few days before delivery is due I get an email on the 23/05 that most of the items are out of stock and won't be shipped. The mail even mentions 'you won't be charged for these'. I have already paid! No mention of a refund or anything of the sort? This was a Mother's Day gift. I find it pathetic that Woolworths can't even keep track of their stock levels.