Please I need help concerning these issues

1. Sometimes in the last quarter of last year,I used the ATM machine owned by union bank which is located within Emedab Petrol Station, Jayi,Abuja.

The transaction failed, but I was debited . Transaction amount is 5000 naira only.

I made official complain at first bank Wuse 2,within Banex Plaza.The issue was dragged until I got tired because I didn't have much time to spend following up the matter.
So I let go.

2. On the 24th of June ,2020.
I tried to pay for fuel at Eterna Feul Station by Banex Junction , Opposite LG house with same First bank ATM card ,again the transaction failed but I was debited.

Amount is 3000 naira only

I waited for reversal and after 1 week. I made an official complain.

They promised to take care of the issue as usual.
I waited for weeks but no refund of the said amount.

I went back to the bank to find out the reason behind the delay.

I was directed to a woman who they said was in charge of such failed transactions.

She attended to me and issued me a reference number stating that the reversal will be done with 3 working days..

My people, it's more than 7 working days now,I have not seen my money nor heard from the bank.

This made me to remember the first transaction that they didn't refund until now, and I began to wonder where actually they problem lies.

Please I need help on how to get to the last logical conclusion of this matter.

The first transaction is 5000 naira only
The second transaction is 3000 naira naira.

Please I need help to recover these said amount.
Evidence of these transactions are on their system which they acknowledged and I will also provide some evidence with me.

Thanks

Write final warning to them and copy CBN

Patented:
Write final warning to them and copy CBN

Thanks, but how I copy CBN or any other financial regulatory bodies..any email ?

Thanks