FNB won't let me downgrade my account

I've been waiting for a whole two months to cancel my FNB private bank account. I called on the 26th of February to downgrade as the account wasn't meeting my needs and as a commission earner, my salary wasn't always the same. I was told it takes 7 days, I called about 2 weeks later and I kept being told that a Rochen Martin would call me. Rochen called me on the 10th of April and unfortunately I was on a work call, she said she'd call in 15 minutes. Until today she hasn't, I've sent emails and held forever on the line. It's really unfair that I have to pay the charges for a private account that I clearly indicated I cannot afford, and I can't even get my Ebucks rewards because I don't even earn enough to qualify,most months anyway. This is not TCF (treating clients fairly) , this is wrong and I'm frustrated because I can't change banks. Can someone please help me