Club Factory — items is large, wanna replace

Address:	11037
Website:	Club factory online shopping

On 27/11/18, I bought 6 items from club factory website as a guest. But one of the item was large on me and that's a black shoes (item no. - SSF[protected]N) so I want to to exchange it with a new size. I don't know how to return and proceed further. If it possible kindly help me to exchange the item.
Kindly contact me as soon as possible.
Contact no. is protected.