Cancellation/ Clearing

I paid R403 on the 31 October 2020 with immediate payment to NDA as they said they are going to remove my name as they blacklisted me because of i cancelled their services. I send proof of payment and when i call and sending the email, they promise to call me back but its not happening.The 24 hours that they promised to remove my name and sending me the letter to show that they removed my name is not happening. I'm tired with your empty promises as i don't owe you, and what I'm asking is a simple thing. Send me the proof of cancellation.