i had similar problem
RFE was issued on aug 29, i got it late on sep 21.
i had sent my RFE on sep 24th, but it was almost 12 weeks
after an RFE was issued and INS not received the RFE,
so i had asked my lawyer to call up INS, immediately my
case was assigned to a lawyer, and we found RFE was
not lost ... it was never opened.
so AVM got updated on Nov 27 for RFE receipt, now iam
waiting for the approval.
some times INS can resend an RFE or they will ask u to
resubmit ur RFE.
but do contact INS before u resend thr RFE
reply.