Double-billed for same meal

On 28 March I had a meal at Adega Restaurant Northcliff. I just received my Standard Bank credit card statement today and I see I was double-billed for that meal. I tried to call and speak to the manager on *** but there was no reply. Standard Bank says that the amount was definitely billed twice. I have submitted a Dispute Claim to Standard Bank to get my refund but I don't see why I should wait weeks to get my money back. I would like Adega Northcliff to refund my R342.00 immediately and also tell me why I was billed twice for the same meal. I don't think I will bother going back there again.