Amazon doesn't allow feedback when it is the seller

You know that "Prime" shipping you pay for? Mine doesn't show up in 2 days a lot any more. There is no "Leave Seller Feedback" button for Amazon sold products. Why is that? That is clearly not fair to other sellers on Amazon who are subject to buyer feedback and is clearly an easily winnable lawsuit for whoever picks that up as an Amazon seller.

I'm not a seller, just an unfortunate buyer who just bought something July 30th that will arrive Aug 6th with a "Prime" label on it and none of that other junk like "ships in two days of order receipt" I've seen before. This isn't the fist issue at all. This order is straight from Amazon, no disclaimers, no third party. Why can I not leave feedback about the seller? I guess they suck that bad.