Visitor visa to Canada help.

I submitted visitor visa to Canada for my parents mid nov 2012 to beijing consulate. and till now there is no news. Starting from 2012 they processed the visa through visa application center but the final part is still done by the consulate. I mailed the application to the consulate directly so I can only check with the consulate directly. Every time I check with them hay said it was in queue for review. But it has been over two months. This is the 4th time my parents applied for visitor visa. I. The past they always get it within 3 weeks. Anybody applied for their parents visa to Canada recently. How long it takes? I also made appointment for them to get us visa. I want to withdraws Canada visa application and apply us visa in person. However if I withdraw Canada visa will they take it as visa rejection and that may not show well if they apple us visa. I want to take my parents here urgently. Any suggestions on how to deal with Canada Beijing consulate.
Thanks