Can't delete a payment reversal

We found a solution!

We spent ages searching through every report, transaction, journal, anything we could. We were ultimately stuck at the stage of the invoice having nothing applied to it apart from the reversal, which counted as a payment, and therefore didn't even allow us to delete the purchase itself.

I logged in to the browser version of MYOB, and after taking a moment to familiarise myself with the different UI, I followed the transaction trail until I found the 'origin' payment of the reversal - somehow attributed to a rarely used asset account rather than being able to pull it out of Electronic Clearing or Trade Creditors. From there, I was able to delete the reversal and start from scratch.

The desktop version still doesn't show the account on Journal Audit reports of what I've done, so I think it must have been a very odd bug in the system. Either way, I'm happy to have my banking all reconciled again!