No responsibility for payments taken via payment gateway

Zero customer service and responsibility for website payments. Placed an order and paid via Instant EFT from my saving account. After a few days checked on my order and it was cancelled. I thought that perhaps the payment didn't go through (even though I received a confirmation email) and accidentally checked the wrong bank account so thought that it didn't. The company also confirmed that this as the reason they cancelled the 1st order - non-payment. So I made another payment from my credit card and I received my order. After realizing that the 1st Instant EFT did in fact go off my account and sending proof to the company I still have not received my refund. They first said that I would receive the money back in my account after 7 days, but after enquiring again they just said that their payment gateway didn't get the money. So its my responsibility to take it up with their payment gateway.. not theirs as they didn't receive the money. I'm sorry, but the responsibility lies with the company - they are responsible for the reliability of their payment gateway - not me! I have already sent proof of that both payments went through so there is nothing else I can do. Absolute shocking service for a company that sells online where we already have to be so careful!