iCloud storage refund

I am using an iPhone SE iOS 9.3.5. I recently upgraded my iCloud storgae plan to the 50GB option on Saturday 10 September 2016. The payment went through on my credit card however my storage plan was not updated. Today, 13 September 2016, I retried to upgrade my iCloud storage plan again. This time my storage plan has been updated but my credit card was charged again. How can I obtain a refund for the 1st upgrade where my storage plan was not updated. I have tried following the support links online but this has been unsuccessful as I live in Namibia and Apple support does not cover this location.