I got a message in my iphone that I have an unknown camera part , I didnt get my camera repaired . why is this telling me this ?

From the article linked to above:

You will see an Unknown Part  message if the camera installation is incomplete or if the camera:

• Was replaced with a nongenuine camera
• Was already used or installed in another iPhone
• Isn't functioning as expected
• This message doesn't affect your ability to use your iPhone or access your camera.

As suggested above, have Apple evaluate it:

Genius Bar Reservation and Apple Support Options - Apple

They can do a lot of the diagnostics remotely.

people report normal hardware defects can give the same message, at any rate you will probably have to have apple or an official repair place have a look at it