Bait and switch

I have ordered from this place three times now and each time I have not received the item I ordered. I have accepted the item the other two times because I did not mind what I was sent; however, to return the item the business requires that the consumer pay for the return postage. This time I will not accept the incorrect item and I will not pay for the return postage because this was their mistake. The business refuses to do anything and now wont return my emails.