Visa Waiver Scheme- failure to collect Green Card on Departure

[immihelp]

I was a visitor to USA , holding an Australian Passport, from July 2006 to Sept 2006 with a month in Canada in August. I departed LAX airport for Australia in mid Sept and have not returned. I now find that my green departure card, which should have been surrendered , is still in my passport. Should I take any action in regards to this ? I do not wish to cause any problems on a future return holiday to USA.

Please advise

Thanking you

[immihelp]

Read https://www.immihelp.com/form-i-94/