ask one question about my son's case

my son's green card was approved on Sept. 2006. when we got it, we found that USCIS made a mistake on his residence starting date. according the approved date, his residence starting date should be Sept.2006. but on my son's green card, Sept. 2003 is his residence starting date. so we sent his card with I-90 form back to USCIS. until now, we have not received his new card.

my son will be 14 years old in half of year, we need to send an application for new card.

could you please give me a advice how to do with this complicated case?

thank you in advace!

di