Speck Case Markings on back cover, help.

I bought my Iphone 4s this past January and promptly put it in a Speck case that I bought at the Apple Store with the phone.

I have used this case every day and my phone has never been out of the case for longer then 5 mins. This weekend I pulled the phone from the case and gave it a cleaning and noticed that the Camera Lense had the SPECK case outline around it. I tried cleaning it with apple suggested ikleen and a micorfiber cloth and the markings remain. Can anyone offer a suggestion? It isn't affecting the operation of my phone it is annoying. The bezel also has marks on it which is annoying. I read online using an abrasive pad can restore it. Why put the phone in the case if this crap is going to happen.

Thank you for your time in reading and if you have a suggestion on how to clean back panel please let me know.

Mike