You will need to contact Amazon direct and let them know you have confirmation that reviews have been left and they aren't showing.
It may be that their system hasn't updated itself over the weekend although this should not be the case as their systems should be very robust. I also assume the reviews weren't all left late on Friday night or over the weekend.
If I remember rightly you get a confirmation that your review has been logged/received by their system when you do it so they should have it stored on some disc somewhere and just need to upload it onto their website.
After all that ramble, you need to contact them so they can investibgate.