Useless company changing debit order date

I asked these assholes to change my debit order date and my banking details! They require 3 months bank statement for this. I sent it on the 18th of December and they still used my old banking details and date. I asked for the last day of the month as my salary goes off on the last day of the month. They debit my account on the 27th. We'll done assholes. DO NOT USE THEM. I JUST HAVE HEADACHES WITH THESE ASSHOLES. REF: 82838