Guess I will have to say this here where it can't be deleted: iTunes U receipts do not show Deepworld account names. We do not have access to any iTunes information. Showing me an iTunes receipt shows only that you did in fact purchase a premium upgrade. It does not in any fashion show ownership of a specific account. Screenshots of a person using an account prove only access, again not ownership. This is called account security and why you should always register your account.
It is that simple. Step 1. Register your account to an email address or a Facebook account that you own and have access to. Step 2. There is no step 2. That's it.
This has been a public service announcement.