What is online msg says? Card Ordered?????
Write a letter to your service center, tell them about it. use copy for ur record, and every month send a letter and keep call 800, untill u receive it.
Sanerio 1. may be they haven't mailed yet somehow. what is online message says?
Sanerio 2. They mailed but somehow mail was undelivered , remember all undelivered mail sent back to USCIS and they put back in file. so may be address mistyped or somthing issue. it can be solved.
Sanerio3. They sent u card, mail delivered sucussfully. but by mistake someone else address. thats is worst sanerio I pray it wouldn't happened.
that make you to apply for duplicate card. and this is headache.
Good LUck and keep sending letter and calling 800