usually if u call below 12 pm on weekday , it goes to what ever service center u want otherwise it goes to general service center and where they dont answer well as per my experience
uscis
for receipt nos
1-800-375-5283
1-2-2-6-2-2-1
for name check or any concerns
1-800-375-5283
1,2,2,6,1 Receipt # ,1,3,4