I've been a working photographer for a little over 20 years, well before we separated both the wife and I worked together as photographers. Now all of our "real" cameras and equipment have allot of miles, and some of the lens have scratches or even dust inside between the glass elements.
My point being is that you can have some very large scratches, dirt or dust on the glass and they will not be that noticeable on your images. Well yes you can find or see some evidence of the scratch, dirt or dust on the finished image, but you have to look really hard.
Same for the image sensors, you can see evidence of dust on the image sensor but again it's not really that easy. For most dust problems you have to look very closely.
I'm not saying that dust will not cause a problem (because YES it will) it just needs to be quite a bit for it to be evident. If your phone/camera is displaying a problem spot on all you images, and you can reproduce this "spot" consistently then take the phone to one of the corporate Verizon store and demand a replacement. Well don't be belligerent, but stress the importance of the camera working properly. Also the phone still should be under warranty, so I would make sure they don't force your into an insurance replacement (that is unless you have a very noticeable ship or scratch on the cameras outside lens element).
if you didn't buy the phone thru VZW, or bought from a third party (like eBay or somewhere else used) then go thru Nokia or go to a Microsoft store.