RFE for Opt extension application.

[pershona]

I applied for my 17 month OPT extension on Mar 22, 2012. USCIS sent
me an RFE asking for proof of diploma conferred Since I graduated this May,2012.
I had already sent them the completion of requirements letter from graduate
division of my school and a letter provided by my graduate advisor confirming
that I have completed my degree requirements.I have my transcripts now
which have the degree updated. but when I called USCIS customer service, they
said if it is specified, then I should specifically submit my diploma certificate
as a proof. My college does not issue the degree certificates before the
deadline USCIS gave me.Please suggest if transcript would be suffice for the RFE.