Unionbank Personal loan overpayment

I have a PL account with Ub under auto debit arrangement. But I paid manually before the day of my due date. Same ang due date with my credit card, so my mistake was i funded my savings account intended to pay my credit card balance. What happened was, it automatically deducted on my SA. I immediately requested for overpayment refund once the manual payment was posted.

Unfortunately today i received an email that my request is not granted without specifying the reason say they cannot disclose the reason.

Eh ang reason naman bakit ako nag manual payment is because maraming beses na ako naka experience ng late charges kahit funded ang account ko on the day of my duedate kasi hindi sila nag auto deduct sa savings ko. Actually maraming cases na ng ganito sa iba pang users (hindi sila nag aauto debit sa duedate).

Anyone experienced this? What would happen kaya? I know i can call them to ask naman pro na frustrate ako dun sa “they cannot disclose line nila sa email..kaya sana sa may mga PL with them kindly share ur experience ano ginawa nyo and learn for my mistake..

Kahit pa it will serve as advance payment, not clear kasi sa resolution. D rin ako makatawag pa tomorrow pa so i will update here.