Poor Service

I am currently overseas and used my Standard Bank Mastercard to withdraw cash from a local ATM. Somehow the transaction was doubled and according to my statement i withdrew more that R10,000, twice. IT is not actually possible to do this and is clearly a technical error. This happened in October of 2015. After a number of international phone calls i was able to have a dispute form emailed to me which i filled in and sent through on the 24th of November. I received an email stating that i would be given feedback by the 8th of January 2016. In the mean time i am being charged interest on my credit card because it looks like i have spent R10,000, which i haven't. On the 8th of Januray i was emailed and told that my dispute was still in progress. I phoned towards the end of January and was told that my dispute was still in progress and that i would be contacted shortly with an update. Again, i'm still being charged interest and they did not contact me. I phoned again this morning (05/02) and was told that the dispute had been sent to the foreign bank on the 2nd of Feb (!!) and the foreign bank had until the 23rd of March to get back to Standard Bank. Why has this taken so long???