Terrible Customer Service

I have tried for the last 2 months to get a refund from Vodacom for continuing to charge me even after I ported out of Vodacom. Everytime I contact their call centre, I get promises of it being sorted within 5 - 7 days and it never ends up happening and it never gets escalated. And I have to waste my time calling Vodacom over and over again. This is terrible customer service.