De*****ed on Uber

Last month I was de*****ed by someone using my card details I their Uber app. Uber said they will refund me after they had done an investigation... There was 4 transactions and they paid me me back for 2 but I'm still waiting for the rest of my money. I have been calling them and sending messages but I haven't received a reply at all.

It's really annoying as they had promised to pay me back but now they are treating a paying customer like trash. Please help me out.