Hello! I am having a problem with my Sigma lens and Sigma service. I have a Sigma 17-70mm 2.8 I was casually taking photos at home when all of a sudden the autofocus stopped working. The lens has never been dropped or hit against anything. I bought the lens only 9 months ago, so I went ahead and sent it to Sigma for repair, since it is under warranty. I got an email a couple of days ago saying that the cost of the repair was going to be $200. I called them immediately and they told me that a piece was broken and that the lens must have been dropped for that to happen, so the warranty would not cover the repair. I told them that the lens has never been dropped/hit and they still do not wan't to honor the warranty. I really do not know what to do. I have called them twice already and their response is the same. Any opinions? Thanks in advance!