It is from my experience.
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It is very stressful, when your CIC application is rejected. You need to ask SINP or other PNP nominate you again. It is not an easy step. You open new account at Express Entry and Job seeker. It is very simple. Then, you have to submit an application form in which you let SINP know detail about your fault. Why your application was rejected. Write carefully with detail supporting documents, write polite letter, submit new document such as proof of financial support (check carefully in SINP website), then you have to wait. It takes about two weeks to get a new nomination if your explanation is good enough.
Some people asked me where we can find the revision form at SINP. Please see the link below
http://www.economy.gov.sk.ca/immigration/request-for-a-revision-and-or-extension-form
As I had explained. It is not easy to renew SINP nomination.
We do not need to say sorry to SINP, since they do not care about that. However, we can let them know that we feel very bad with our mistake. It is our mistake not SINP or CIC. We try to explain why it was happened. For example, if we do not have enough police check, tell them the reason. Then, we have to give the proof that we have all police check at the current time, or we had applied all the police check. It means that our CIC application will be OK.
Good luck to all,