incorrect debit order deduction dates

I am so disgusted with Old Mutual. My salary date is the 25th of each month, regardless of which day the 25th falls on. This is the 2nd month that Old Mutual debits my bank account before my salary is paid. This is not acceptable at all. I signed a contract for a specific date and that does not give Old Mutual the right to debit my account before my salary date, regardless if there are funds available in my bank account. Very unhappy client.