Most likely, the small pin in the device that creates contact with the battery has been bent down. This causes the device to not receive power from the battery and therefore not work.
The pin that connects to the battery is located on the right side of the device and is slightly bent inward/downward.
What you can try is to bend the pin up using a pointed knife or similar. If the pin is bent outward, the battery can make better contact and the device should start working normally again.
Feel free to try this, and if it does not work, you are welcome to send us an email at [email protected] and we will take a closer look at what the issue might be.