I totally agree, contact the person or company that you purchased this lens from and return and demand that you receive an immediate refund, depending on where you purchased this lens you should have various ways to resolve this issue

If the problem is located on the inside of the lens then it's probably not a "finger smudge", instead like I've said earlier it appears to me that the lens coating on the inside of the lens is beginning to de-laminate. This can occur for various reasons including the lens being left in direct sunlight for an extended period of time, causing the coating to become over heated and causing it to peel or de-laminate.

I've seen this happen when someone had left their lens in their car that was sitting in direct sunlight for several days. I live in Hawaii and our cars get very hot when parked outside in direct sunlight for extended periods of time. Because of this fact I never allow my lenses to sit in direct sunlight, for example, I shoot a lot of surfing events and I always cover my lens with something, a towel, my t-shirt, a cloth, anything to avoid direct contact from the sun while I'm out doors shooting.

I'll admit that this isn't the case in every instant but I've spoken with a lot of professional cameramen who've experienced this issue.

I've been in the photography/video business for 35+ years and I've seen this problem before. It looks like the coating on the lens is beginning to peel.

Here's a brief explanation of these coatings:

Camera lens optical coatings almost always use a thin Magnesium Flouride (MgFL) layer. A vacuum chamber is used to apply them. A solitary optical coating will typically be a subtle blue color as one views the surface of the lens at a slight angle. Multi-Coated lens most often have a purple or green tint to the exterior surface.

There are various types of coatings and each has it's own reason for being used. Over time and through use, these coatings can possibly begin to peel from the lens causing this type of problem.

Here's a article which explains camera lens coatings and what's used to coat these lenses:

http://www.vistaview360.com/photography/optical_coating.htm

I hope this helps ...