No refund for a duplicate payment

Stayed at Kingdom Resort in September 2017. I went for dinner at the Boma on the 24th of September. The speedpoint showed that the first payment was rejected and had to do it again. A few days when looking at my bank statement I realised the payment was duplicated. After phone call, emails and assurances that I would get a refund, nothing has happened and now there are no responses to my emails/calls.