No refund

I received a gift of 4 duvet covers from Woolworths. After washing them with fabric softer they had this bad plastic smell, I treid to sleep with it but took if off in the night because the smell was sooo potent and bad, smelt like chemicals in the fabric used. These sets were about R600 each!!! They can no longer fine the item on the system therefore can't give me any money nik, or store credit. This is unacceptable, just throwing away R2000 worth of bed linen!! They said nothing they can do. But only send it to factory for testing and then maybe give me R50 per item. What must I do?!!!??