How do you just pay money in a wrong account numbe

I have this situation. I was expecting money from a ABSA customer to my Standard bank account. The account number used was incomplete so ABSA allows this funds to be transferred towards a Unknown students account just adding an extra zero in front of the incomplete number - and allows the transaction to go though even though the students name and mine do not even look the same - So how secure is the internet banking system. where is the protection against things like this?? Now unfortunately they expect me to get this money back myself???? How do you justify your mistake and expect me to try and make my own arrangements to sort out what you did wrong in the first place. Why is it that If I do an internet transfer to another account the funds will not go anywhere if the account number is incomplete and the persons name or account name is not correct??? this is *******. This student cant pay me back this money and feels it was not his fault and I agree that ABSA must take responsibility for this. This might not be a lot of money for mr Marcus but to me this is a **** load of money to just loose like this because you just pull up your shoulders