Unfortunately, any PM account that has been dormant for 90 days or more is removed and the associated plan and phone number lost. That would be why your old login doesn't work anymore. When you activate a new account with a new SIM, you would have to use a different e-mail address upon activation. Afterward, you can go back into your PM self-serve account to change the e-mail address to whatever you want.
For community rewards, previous community activity from when you had the old account will provide no benefit. For future community rewards to accrue to your PM account, you must make sure that your e-mail addresses in your self-serve account and your community account match, at least by the time the monthy community rewards are credited (usually between the 7th to 10th of the next month after the month in question).
The 2-year anniversary badge was given to anybody who had a community account at the time PM reached its 2-yr anniversary in its current incarnation. It actually doesn't relfect how long any particular customer has been with PM. If you are referring to the fact that you've been with PM previously and might be in line for loyalty rewards, your new account would not be associated with your previous time with PM.
More about rewards here: http://productioncommunity.publicmobile.ca/t5/Knowledge-Base/General-Reward-Rules/ta-p/164
