Pathetic Vodacom *****ing Money

My current service provider, Vodacom, deducted R5000 from my account for a handset upgrade, after it was agreed that the handset will be paid monthly(x24) like normally. After disputing this, I am still struggling to get anyone to help me. They won't follow up on my logged SR's. They basically ignore my dispute. It has been 2 weeks. Please help. I've been a customer for at least 10 years. It's a disgrace.