False Advertising and products not being collected for refund

I ordered a few tops online, as I was specifically looking for cotton material. The website stated 95% cotton for the cami's I ordered. When receiving the goods, they were all made from 100% recycled material. Not a stitch of cotton. I immediately made contact with them (25 November) and they have still not arranged collection. Approximately 10 emails and phone calls to the customer care number, all gets answered with a standard reply that Dawn Wing couriers will make contact and they have escalated my query. Cotton on is just avoiding having to refund. And the issue of FALSE ADVERTISING needs to be addressed immediately.