Debit order dates

With FNB setting up a debit order date that suits the client means nothing to them. I asked for my debit order dates to be on the 1st of every month. Today is the 16th and they took all my transport money for my loan. I always pay, every month, are never in arrears, so why do they just pick a debit order date that suits THEM. I'm very dissatisfied with this service. And talking to their assistants on the app is very frustrating. After explaining your problem to 10 people you get nowhere.