In order to hard reset a Samsung A837 Rugby, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Samsung A837 Rugby device will be brought back to the default configuration of a brand new device.
1. Start by pressing Left Soft key.
2. Afterwards, select Settings > Reset Settings > Phone Settings > Ok.
3. Enter the phone's code (0000 by default) and select Yes. Done!