Unauthorized debits

Now what is the use of signing an agreement/contract with A&G for a debit order to go off on a specific date? A&G now decides to collect premiums over a 3 day period? I'm of the opinion that if we agreed on the 15th of the month then you stick to the 15th. It's none of A&Gs business if I have money in my account on the 14th and they have no business touching it. I feel violated and powerless besides my account going into overdraft on the 14th when our agreed date is the 15th. Disgusted