Crack in Pentax K10D body

First you should only have submitted it for repair after getting the dealer to sign a document detailing all visible defects. Othewise you are just arguing over whether the camera was damaged before sending it away for servicing.

It would be the dealers resposnibility to make sure tha camera was taken care of during the repair, even if the damage was not their fault. It is up tho them to make sure that the repair is carried out satifactorily. They should take it up with their repairer if they have a problem. It should be a Pentax approved repaired for such a recent model, so this should not be a problem for them.

Getting them to sign a description as outlined, will also protect the dealer. (And the repairer) as this will hlp establish that the camera was OK when they sent it to the repairer, but they must ensure that it is delivered to the repairer in the same condition, so if sent by post it is their respinsibility to make sure it arrives in good condition. (Often the repairer arranges whipping though, so that they can ensure that the service is adequate. Trust me, some of the things I get in for repair are applaingly packed,)

To rectify the problem the body panel will need replacing and this will mean the part will need to be ordered from Pentax. It won't be cheap, but that should not be your problem. You did not cause the damage.

This damage alone though should not prevent the camer being used, as this is quite a robust camera designed to take rough handling. That is not however the point.

If you cannot get the dealer to admit responsibilty, then unfortunatley there is little you can do except contact Pentax directly with a complaint. To sell new Pentax cameras they must be a licenced dealer, and Pentax can use this to apply pressure if they think that you have reasonable cause for complaint.