Refund Long overdue

Refund for out of stock item I bought ballet shoes in April online and then days later after receiving the other items I got an email informing me that the shoes could not be shipped because they are out of stock and that I will get a voucher for a refund. I waited until I forget the voucher was never sent then I called them last week when I remembered and I was told the voucher was sent to my email but there is nothing on my email and I asked the guy I spoke to who was rude to resend it because I never received it and I was told it can't be resent he'll have to send a request for it to be resent which will take 24 hours then he dropped the phone on my ear. Till today there voucher has not been sent and this is an order that was made in April by the way.