請教P, 8大師: Service Request Status-Under Review

pjiang, 863211大師，

I called CIS yesterday for a service request. Today got an email saying
"The status of this service request is:
Your case is currently under review. You should receive a decision or notice of other action within 60 days of the date of this letter."

EB3/NSC
PD: May,2003

My case has been staying initial review for years. What does it mean by case is currently under review？

Should I contact my congressman now? I'm afraid that if I don't act now, my PD will become unavailable like 3 years ago.

Thank you for your help in advance!