Waiting for my refund from Mango

I bought a trench coat online from Mango, completed the necessary online forwarding documentation and received the trench coat. It didn't fit so I did an online return and on 11 April DPD Laser came back and fetched my parcel. Two weeks later I phoned DPD Laser only to be told that they still hadn't dispatched the parcel to Mango. I find this totally unacceptable that it is now over a month and I cannot speak to anyone at the courier service who can help and I sit waiting for my refund. If I was Mango I would change my courier service to someone more reliable and contactable.