STILL WAITING ON MR PRICE ONLINE REFUND!!!

HORRIFIED with the bad online service of Mr price online. This has happened before and they will never refund you so they are blatantly *****ing. Email after email. You get answered with an automatic email. I bought a cushion on line, paid for it. Then I get an email telling me that that item is out of stock now. So I emailed them what now I want to be refunded. Yes they will refund me as soon as I pick up the other item on the order that they had stock of. I informed them that I picked up the item. Lady at the Mr home said that the online department must refund me with the voucher. They cant take the cushion off that I didn't receive. I told her thats very bad service. I can return stock to them and they refund me, but if they owe me something they cant refun. d me. How does that work. She tokd me that they get numerous complaints about the online service. So I'm still waiting for my refund. What to do???