Cancelled order and still not refund

I ordered Online on Black Friday 4 sneakers, they cancelled 3 sneakers on Sunday the 1st on the order reasoning being that they were out of stock. Where as when i ordered they were in stock. The promised i would be refund within 3days, its now Monday the 9th i still have received my money back and i also have not received the sneaker that was not cancelled. I have been calling and email them, they haven't processed my other sneaker and i haven't received an invoice for it nor have i received my money back. They have bad client services because they know even thinking about the client, i cant even buy another sneaker if i see one now because i dont have money for it.