Stop debicheck on standard Bank account please

I have requested IQ Academy to immediately stop making debit order on my standard Bank account as I am no longer using it for salary related matters. I have supp**** new banking details but they again tried to debit and this cause a charge of R147 everytime they do that. It is also surprising that they will debit on a date suitable for them. I am no longer using these bank details, IQ academy you have my new banking details please use them.