In my experience, canon factory service has been very reasonable if you give them an argument Be polite, but inquire a lot, and be ready to point out things that would seem like they should be covered by Canon. I.e., was the lens on the camera with a filter as to be supposedly 'sealed'? It may be that the lens simply sustained more damage than you realized, but it can't hurt to push gently to see if you can get a partial reduction, being very nice to the individual you're speaking to, but implying criticism of the policy, if you think it's deserved.