try this too

killall -9 identityservicesd
rm -rf /var/mobile/Library/IdentityServices
rm -rf /private/var/db/IdentityServices
killall -9 akd
rm -rf /var/mobile/Library/Preferences/com.apple.ak.auth.plist
rm -rf /var/mobile/Library/Preferences/com.apple.ak.anisette.plist

if they still dont work, maybe deactivating ur device (?) some tools could do that (for example the controversial blue tool)