Misrepresentation and misinformation from Builders

I ordered a dishwasher online on the 24th of August and paid by credit card order number ***) Builders phoned me a couple of days later to say they do not have the dishwasher in stock but will carry on looking. I subsequently found another dishwasher at another store and cancelled my online order with Builders. On the 28th of August I cancelled the order and on the cancellation order it explicitly stated that because I paid by credit card I would be refunded immediately. After the cancellation I followed up with Builders as I did not receive the refund in the my account. There was some story about it went into my online account and from there it will take 7 to 14 working days to refund me. That is not what the cancellation e-mail said. This is a clear case of misrepresentation and miscommunication. I am out of pocket with this amount as I was under the impression if would take a few days to resolve this. However when you speak to the agents they are quite comfortable talking from their talk sheet and despite the fact that I have in black and white that i would be refunded immediately they do not care. I am obviously not valued as a customer. Why have two contradicting statements. Surely what was promised to me as a customer should be adhered to. Why must I wait for my refund when you as Builders are sending out miscommunication.