Debit order mess

My debit order for my device is scheduled for the 20th of each month. My salary got deposited into my account on the 20th as well. However the debit order failed because it went off before my salary came into my account and I will now be charged a penalty fee for this. Our agreement was for the 20th when my salary comes in. I am now sitting with an unpaid debit order on my name(which will affect my credit record negatively) and I am going to be charged a penalty for their mistake. Tried phoning in to the call centre but once again they were useless and nobody had a clue what I was talking about.