@Robin ******
you weren't on a one year ED visa :O you were on extensions of stays that you got every 90 days from the immigration office.
All you did was change the REASON for your extension from education to being over 50 by canceling your ED extension and applying for one based on being over 50 (retirement).
Unless you couldn't meet the financial requirements on your own you didn't need an agent down there to 'push paper' for you. That's changing the reason for an extension is an easy one to do on your own, IF you are on extensions of stays NOT on the original entry from the visa.