@analogica I work in the complaints investigation dept of an Irish bank and sometimes encounter this complaint. There are a couple things to bear in mind.
First a missed payment only reports to the CCR if its owed for more than a few days so if you have made the repayment it shouldnt impact your CCR.
Second Ive heard secondhand that CCR doesnt show one missed payment only two or more but you might ask them yourself, check out
www.centralcreditregister.ie.
Third banks sometimes agree to refund missed payment charges if you ask nicely so I'd recommend trying that. I dont necessarily agree to fees being charged each and every time something goes wrong but its a deterrent and it works.
Fourthly, youve asked why the bank didnt show preference for bank loan repayments over this other unspecified payment. Do you believe bank staff go in and manually process debit transactions one by one? This is all automated and if the bank were to somehow filter bank vs non bank transactions im sure people would complain their loan was paid but their rent wasnt, etc etc.
Fifthly, there is no credit score in Ireland and never has been.
Finally, use the tools the bank gives you to manage your finances better. This couldve been avoided and your post reeks of blaming the bank for your mistake. As I said above if you ask nicely they may refund the fee but this was 100% your fault and if you go in all guns blazing theyll fairly tell you no dice.