Vodacom staff member fails to respond to a customer query

Dear Vodacom, my monthly balances have again not been carried over correctly at the end of January. I finished 31 January with 50 minutes available for the January period and started on 1 February with 98 allocated which according to my calculations, leaves me short of 30 minutes talk-time. I visited your Vodacom shop in Morning Glen Mall on Friday 1 February and spoke with the Manager, Ibrahim Mulla who promised to investigate / email me. Up to this day (6 February), I have not received any response from him, in spite of asking him daily for a response. He promises to email me the letter/query he sent to Vodacom on the 1st, but then just ignores me. What is a Vodacom customer to do when you have this problem monthly, visit one of your stores to resolve it and get ignored as a result? Is this really how you treat your customers? This is not a new problem as I experience it basically on a monthly basis. I make the effort to try and resolve it and then get "blocked out" by your staff. Queries in the past resulted in unsatisfactory responses, i.e. that the balances included previous month's usage. This is not correct as I strictly monitor my month-end balances and they do not align with new month's allocations - i.e. the 30 minute discrepancy experienced end of January. I would think that the balances are carried over via electronic programming and am thus perplexed that Vodacom gets it wrong on a regular basis. I am really tired of having the same issue with Vodacom every 30 days and on top of it getting no service from a Vodacom outlet - this time the one at Morning Glen. I don't want to call your customer services as I have done so on many occasions to receive said response (your call centre staff obviously do not understand the calculations from month-to month either) or to wait up to two weeks for balances to be corrected, if I am lucky. So this matter is now reported to you on a social media platform in the hope that you will resolve it and do the balance transfers correctly from now on. Or do you want your customers to all move to another subscriber? I have been a loyal customer of Vodacom since 1999 and really do not appreciate this constant conflict with my account and being disregarded by your staff.