BAD SERVICE!!!!!

On the 4th of June I placed an order with Superbalist for a swim wear, parcel was delivered 06/06/2019. When I opened the bag it indeed contained of the swimwear I had ordered. I had ordered a Large, but that I did not receive the correct size. On the label it showed Medium and on the tag it was Large. I went on their website to process a return but it was rejected with no reason given. I clearly stated my reason for wishing to return the item. I did not even attempt to fit the item on as I could see there was no way it would fit me. I then sent an email stating the error in my parcel, and I was advised to send the pictures, which I did. I received a response advising that a manual collection will be done and I will be refunded. The courier called on Friday 14/06/2019 confirming the pick-up for the same day. The courier did not collect nor bother to tell me the reason for not collecting the parcel. Till this day I still have the parcel. And no one is replying to my email anymore. I am dissatisfied with this type of service.