I’ve been overcharged

A few weeks back, I discovered that DSTV have been over charging me for my plan. I’ve been streaming only for the last few years and they have been charging me decoder prices. I called your call centre and the lady I spoke to agreed and said I’ve been incorrectly billed and it shows on your system that I’ve been streaming. She said she was escalating to your finance and someone would contact me and my money that I’ve overpaid will be credited. It’s been over 3 weeks and I’m due to renew my subscription and still this issue not solved. I need this attended to as a matter of urgency.