Power Door Locks Not Working problems of the 2011 Toyota RAV4

About a year ago, I packed my car to go on vacation. I put the dog in the car and returned to my house to get something. When I returned to the car, it was locked. I assumed I had inadvertently pushed the lock button on the remote so ignored it. Over the last 6 months, this has happened more frequently. On July 6, 2015, my mother and I went to walmart. I went in and she stayed in the car. When I returned the door was locked and she could not open it with the power door lock on the door, so I had to use my remote. Today, I was taking things out of the rear compartment and the keys were hanging in the door to the house. I heard the car door lock itself. I took it to the dealership and we could open the door and watch it lock itself in less than one minute of being opened. During that time, the inside electronic door locks would not work to open the door, it would only open with the remote or the manual door lock. The dealership wants me to bring the car in for inspection tomorrow, but Toyota corporate will not assure me that I won't have to pay for the diagnosis of this problem. I feel this is a safety feature of the Rav4 and they should be willing to diagnose this for free. If they don't, I will not take the car in. I told them I am very concerned that this may happen to someone else and could involve children getting locked in a car without the ability to unlock the door (if they don't know how to use the manual lock).

Shortly after purchasing my Toyota rav 4 in 2011, brand new, my husband stated the rear driver's side automatic door lock would not always engage and lock when he locked the car. He said it didn't matter if the car was stationary or in motion. He kept stating he was going to take it to the Toyota dealership where he purchased the vehicle before his warranty ran out. Unfortunately, he got very sick and passed away in 2014. Now the rear driver's door will not lock at all, whether it is stationary or moving. This problem makes me feel unsafe at all times.