Return not collected!!!

I placed an order *** on the 20.08.2015 and received my very efficiently on the 24.08.2015<br> However, I wanted to have it exchanged for a different size and booked a return *** on the 25.08.2015 It has yet to be collected and I even went to through the chat facility and still nothing happened. I am highly upset because I need this shoes and I cant place a new order until the items are collected and a store credit passed. it makes me feel that I would rather haven my money refunded and purchase elsewhere.