Refused to cancel my account

I opened a account now I've decided to cancel the account they already told me on 15 this month they will take 544 for 36 months, as I was counting the money it was 19,800 I told them to cancel they refused I went there sleep master to the guy Anathi they never bother to cancel my debit order I'm stressed and frustrated because I'm not longer needing the account I will lay bye the bed but they are refusing I was helped by Unathi in Bay West mall