They refuse to refund

Bought a Polo shoe and it was delivered on the 11th of November but it was too big for me and i didn't like the condition it was in so i decided to take the shoe back for a refund. Indeed on Monday the 15th a delivery guy came to fetch it, while i was waiting for my refund i then got an email from them saying they can't refund because the shoe was in a bad condition. I emailed them back saying i never worn the shoe, i got them in that condition. After that they were silent until i decided to write to them again yesterday and there was no reply. Then today i called and a lady i was speaking to said they just sent an email to me few minutes ago which i haven't received even now. Please guys i need my refund asap My contacts