Credit score affected due to internal issues

I app**** for a holiday payment and was approved. Somehow the loan department did not get the memo and now my credit score is down 24 points because i “missed a payment”. What is painful is that they didn’t even attempt to deduct the money via debit order they just decided in January that I owe them. I called and got it sorted it out but imagine my surprised this week when I checked ClearScore and my credit score went down and it shows a missed payment. I have never missed a payment in my life. I have never used any bank but standard bank keeps pushing me to look else where .