I submitted my app in February and wrote out a fee enumeration because I also had the problem where there was no payment detail. This makes for a total of $1380. I think the fees increased in April though, so your prices may be different.
Sponsorship fee ($75)
Principal Applicant Processing Fee ($475)
Right of Permanent Residence Fee ($490)
Biometrics Fee ($85)
Work Permit Processing Fee ($155)
Open Work Permit Holder Fee ($100)
Edit: According to the basic guide, it looks like the only change is that the Right of Permanent Residence Fee went up $10. I think you may have not paid for the Open Work Permit Holder Fee. I think they typically send back applications that have the incorrect fees paid. It may be worth paying the $100 OWP Holder Fee and sending a web form with both receipts. Hope someone who has experienced this can give more input though.