black listed for no reason

My bond application was declined and their reason was that I had bad credit and was listed by vodacom. I paid up and called my contract over 3 years ago with vodacom. Firstly, it was an absolute nightmare getting through to the call center, which only allows you to go through when you have a vodacom number and simply cuts the call when you don't have one. Long story short, when I eventually went to a vodashop, I was told that I owed R11 and that's why I was listed. I gladly paid the R11 and was told that a paid up letter would be sent to me within 7 days. 2 months later, I'm still waiting.