Final update :
Google is unable to resolve this issue. I've provided them, with certainty, the email account and method of payment that was used for the purchase. (Google Play Store Credit). Everything related to the app has disappeared from my account. This is the SECOND time this has happened...
UPDATE :
Contacted by Technimo/ iReal Pro directly. Helpful in attempting to solve the problem. Though, there was no resolution. Directed to Google Play Store/ Customer Support. Very helpful, though solutions are somewhat useless, clearing data/ cache of certain apps. Still no resolution, even...
I've seen others on the forum have similar issues, though have not found a resolution. Technimo people gave prompt reply and are trying to figure it out from their end.
The problem:
After a hard reset of my phone (Nexus 6) - app does not appear in my list of paid apps on the Google Play store...