The login ID is not the game ID. The login ID is never removed as it is like the account number and is private information between HTC and you.
Use a different login ID to create the account, then when the game promots you to enter a game ID, try using your old one. If it has been a while, it is should be available. If it is not available contact Carrie (billing@hitechcreations.com 817-251-1540) to get her to manually clear it out.