Complaint Regarding Incorrect Debit Order Date

I am now regretting using this service to begin with. I had spoken to a consultant and specifically told her that whatever amount they need to be debited should be done on the 25th and she decided to make the debit order on the 1st of every month because I received a message stating I will be in arrears if I don’t pay. I called again to express my frustration to another consultant and she said that the first consultant made a mistake with not informing me about the debit date and she would fix it. To my surprise she clearly DID NOT FIX IT because they just debited again yesterday but there is nothing in my account. Now what must I do at this point because I SPECIFICALLY said the 25th but they put it on 1st again.