locks go up and down

I had my 99 bosh range rover at a mechanics for a muffler replacement. I told the mechanic that I would not be able to pick up the car until the evening and asked him to put the key, (a plain rr key), in center console box and lock the car. yesterday evening I brought an older alarm key, ( battery on key seemed to be dead) , to unlock my car and drive home. I was able to unlock the car and when I turned the key in the ignition, nothing happened. I retrieved the key from the console box and tried to use it. Nothing at all, engine would not turn. I thought maybe I should lock the car again with the original key, then unlock it and try again. when I did this the locks started going up down, up and down, up and down, on their own. I managed to get them stop by messing around with the key and tried to start the car again, no luck, the engine would not turn at all. I tried tolock the car so I could go home and the locks started up again. I had to disconnect the battery so the locks would stop.
I do not know what to do about this.
robert