Where to report?

Hello, I've been researching on how to handle this type of situation. I've read a lot about filing a complant sa SEC with proof and screenshots. My loan is OD for a day. One day lang. Can anybody share their thoughts on where to file the complaint and which departments should be cc'd?

Just to be clear, I am planning to pay. I'm just waiting for funds to arrive by the end of next week. I don't think being overdue for a day is a good valid reason to send death threats especially that one screenshot in here.