Hitesh - II am also waiting for request letter for wife's PCC from Singapore - my medicals passed on Jul 21 but no request letter or ARD from CIC to date (quite surprised). I had called CIC couple of weeks back asking about this and the person I spoke to on the phone was kind enough to send me the link to a PDF which you can fill yourself and submit as an official request letter if you have not yet received one from CIC - here is the link
http://www.cic.gc.ca/english/information/applications/guides/pdf/PC_LetterA_e.pdf
Basically I am the PA and I had earlier appealed to SPF with ITA and marriage certificate but the rejected it saying request letter is not in spouse name - I took a chance with this PDF above and they approved the appeal and now I have submitter her prints. Hope this helps you and others in a similar situation. I wanted to save time rather than waiting for the ADR after which it will easily take a month looking at SPF processing times.