Unauthorized debit order

have a money builder savings account with ABSA. On 22/12/2015, two debit orders went through on the account of R1473.77 each. I have at no point given anyone authorisation for such debits. That account is not even supposed to have debit orders on it. I insist that the amounts be credited back to my account. WHO GAVE VIRGIN THE RIGHT TO DO THIS! I was making monthly payments and even emailed an arrangement till when my circumstances change!!!!