Visa stamped on wrong passport

[jijuanair]

Hello,

My friend arrived with his wife 2 weeks back.He has been working in Canada for 2 years now his wife got the visitor visa and he brought her to Canada.
2 weeks after bringing her he noticed that her passport doesn't have the visitor visa stamp.He found that in his passport airport emigration stamped a Visitor Visa(which is not needed as he is working in Canada on a work permit).
Seems like the people at airport stamped the wrong passport.

Question:
How can he correct this situation?

Thanks EveryOne

 

[Pangit]

Hi! In my idea that's a spousal visa, if I'm not mistaken!