2 weeks and no collection and refund

My order arrived and the product is clearly mis-sized or a second as I have been wearing this size and brand for over 30 years. I then requested a return and refund online. Despite receiving 2 emails confirming the date on which the courier will collect on both occasions no courier arrived. I have just spoken to a customer service agent named Kim who said that she would book again for the courier to collect. He attitude was as though she was doing me a favour, however I am paying for this service. She then said she would escalate to the operations manager of the courier company.......she didn't know his name but then said it was Nico. I have waited 2 weeks for collection and refund and I believe I will still be waiting in another week as no one seems to care as they have my money.