I don't know who needs to see this, but if you have a failed transaction/transaction error with any Nigerian bank and it's taking more than normal to get your money back, here's all you need to do:

1. Send a mail to Central Bank's Consumer Protection Department (CPD) via the email address cpd@cbn.gov.ng with all the relevant details, and COPY (Cc) your bank's customer care email. See the image below.
Has Your Bank Debited Your Account for a Failed Transaction? Do This to Get a Refund in Few Minutes
2. Add a suitable subject to your email, e.g., NO REFUND FOR A FAILED TRANSACTION.

3. In the COMPOSE EMAIL box, state your complaint. Tell Central Bank what has really happened.

4. Endeavour to attach pictures, texts, or any relevant document as evidence.

5. State categorically that you are aware that there's an extra ₦10,000 fine to be paid to you as penalty and damages for the "stress and inconvenience" caused by your bank.

6. Click on the send button.

7. Take a chill pill and watch your bank reverse your money in 30 minutes.