Fail to refund on their mistake

I have a R50 rand limit on my 3G account, but Vodacom charged me R1471 for additional data for my March account Invoice number - B ********** 53 On 26 April they admitted that it was a fault on their side and they will refund the corporate account by R1392. Query number - EC-0CI6-1FM1DT It is now 19 September and all I hear is excuses about processes that need to be followed or that is not in place. I am waiting for almost 5 months now It looks like they want to use corporate bureaucracy to wiggle out of paying