One year on waiting for my refund and paid up letter

I ended my contract with Cell C and rather moved over to a different network provider because Cell C has really gone down the drain over the years. My contract ended and I requested a paid up letter and refund on my credit last year December (yes, you read correct, LAST YEAR DECEMBER), and did multiple follow ups on this during this year. I was promised by Chanel Ngwenya and Duduzile Molefe that my refund will be processed within 3-4 working days. Every time i contact customer care, I am given a new reference number with an automated response that "A consultant from finance department will contact me in 2 business days". I am STILL awaiting this apparent call. Still no paid up letter, still no refund. My advice to all my friends and family regarding a network provider is STAY THE HELL AWAY FROM CELL C! Their consultants don't know anything, you get transferred from pillar to post and they affect your credit score because you have an open account with them even though your account is long time paid up. Even though I had moved on to greener pastures, they still seem to be a pain in my behind. Wow