Fnb refuse to close my cheque account

I've been trying to close my account with FNB for the last 3 months. I have logged close to 5 references and their secure chat consultants are truly useless. Each time I get a refrence but the account is not closed..in the meantime I need to keep paying bank charges for an account i do not want or need . Instead they send someone to call me to upgrade and account they can clearly see is not in use. I'm so tired of fnb .. they must change they slogan because they not helping anyone