Removed the battery and put it back and restart your phone. Wait for it to upload itself. If it doesn't work check your battery or put it on charge. Hope it works
blackberry swiss army knife (bbsak) just google it, it will be your first result it will wipe the device clean then you click on load OS to put your device software back on. Be warned all your apps will be gone. Hopefully you were running blackberry protect so you can get back your contacts. good luck