Vodacom unwarranted blacklisting

Last year I prematurely cancelled my Vodacom account. I paid the the outstanding balance, sent proof of payment and a copy of my ID (as requested). I thought everything was fine as I didn't hear from Vodacom again. Last week I wanted to take out a student loan for my son, only to be told by my bank, that I have been blacklisted by Vodacom. I have tried to email but no response. I have tried to phone, but keep getting sent from the Cancellations dept, to the Accounts dept and back to Cancellations without any success, this after waiting on hold for 10 minutes at a time. All I want is the blacklisting to be cleared. I did nothing wrong and paid up in full like a good citizen. This is the apparent reward one gets for good behaviour. I will never deal with Vodacom again.