They'd take a month or month and half to return your application.
Here is my exp:
I filed my EAD on Oct 14th (Paper filing), never got receipt #..I efiled again on Nov 14th. Today 11/21 - They returned my old EAD application (rejected because the I-765 form was not signed). But took month and a week to returned that.
It has receipt # too and TSC asked me to sign that resend the whole package for speed up the process. (But i have already efiled).
Now i have no idea to withdraw the returned application or leave as it is. if you have enough time, then wait for their returned mail and refile. If not E-File.
Experts, comment please..