Is it possible that visa officer firstly send approval letter for the study permit and then after some hours refusal letter for the visa. As i have read some where this happens to someone. It can be true?
You receive the following e-mails in your CIC account :
Application confirmation
Biometrics correspondence
VISA rejection or Passport request letter and Correspondence letter
Approved study permit correspondence letter(This is a letter that you receive post verification of your passport. They check if your passport is valid)
A PPR does mean that your application is approved and is pending the verification of your travel document i.e. Passport. If there is a problem with your passport then they can send a rejection letter on your application.
Else I haven't heard of case where an approved study permit correspondence letter was issued post passport verification and subsequent rejection letter was sent afterwards.