Fraudulent purchases done after my card was cloned at Black Bamboo

On Tuesday 5 June 2018 I went to your restaurant in Menlyn(Black Bamboo). It was my sisters birthday and after rthe dinner we had I paid for the bill. This was on Tuesday night and on Wednesday I came to work and today at 18:37 I received a message from my bank notifying me that I purchased something to the value of R4 000.00 from Bag It. And when I called my bank I was told that the purchases that were made were via my card. The only explanation I gave is that it was cloned at your restaurant as this was the last place I used. Tell me if I, as the client do not feel safe at your place, how do you expect us to come back there again. I'm sitting at work and R4 000.00 comes off fro my account please come back to me and tell me how did such a thing happen at your place. I need answers. I'm about to take this to all social media's. I need answers.