Your battery is bad. It probably has expanded so that it is now jammed against the case and metal memory card separator. Otherwise, the battery would just fall out when you release the battery lock at the bottom of the battery. If you are lucky, the battery has not yet leaked. You will have to pull the battery out manually. This can be hard to do because you cannot easily get a grip on it. I removed my battery that failed this way by inserting a sharp pointed knife into the side of the battery case near the end of the battery so that I could pry the battery out. Note that when you do this you will puncture the battery seal and allow internal liquid and gas to escape. So turn the camera so that nothing runs back inside the camera body. If the battery is stubborn, try to work around the bottom prying from different angles a little at a time. You may be able to slowly rock it loose. The battery is a Samsung SLB-10A. The battery is cheap and readily available on Amazon and other sites.