Earlier this month I sailed on the Enchantment of the Seas. On the second day of the cruise I was looking for a pen and went through all the cabinets. I found a camera, charger and several other items of value. I took them to the Customer Service Desk and turned them in. The young lady who took them said they would review the logs and see if anyone had reported them lost. She also said something that surprised me. She said very little property gets turned in by passengers, they usually keep whatever they find. That is not my style and I figured whoever left it there probably had all their pictures on there and it would be quite a loss to them.
I think if I found a camera I would try to handle returning it to the owners myself. You know the cruise line, dates they sailed and have pictures (probably) of them and family. There may even be something that gives away where they live, etc. With the widespread use of social media by almost everyone you could post messages on all of them and discussion boards like this.
As for the OP...I can't see ceasing to do business over something that was your fault. The customer service should have been better...but you should have been more careful. As for criminal charges, against whom would you file? If the door was EVERY left open it could be any passenger on the ship. It could be anyone in Customer Service on the ship or any crew member with access behind the counter. It could have been put aside in the cabin while it was being prepped and they forgot to grab it an turn it in...therefore it could have been kept by the next passengers staying in the cabin.