*WORST SERVICE EVER AT CELL C*

So we finally had it with cellc. I've been complaining with cell with themselves and here on hello Peter. But still nothing is happening. My dad's account has been paid in fully but still he's on the blacklist. Nothing has been removed from his name. Everytime they just phone and say we will remove your name in 2 to 15 working days. It's been several months now. The account was paid in full in November 2022. They said they did took my dad's name of on their system, but they didn't his name is still blacklisted by Cell C. What is the next step we can take to clear my dad's name. Because Cell C is so full of stories and empty promises. We are so had with these people. Please can someone assist to help us solve this problem!!!