Dont panic when your contact lists are gone!

It happened NOT to my C3 but to my new cheap C2 dual-simmed phone. The contact lists were gone, or was emptied and were not displayed on the screen.

What happens usually is that the battery is almost totally drained. Almost since you can still access the phone screen. Remove the battery at the back, and place it back again. Then fully recharge it before use. The contact lists will be back. So don not panic, like resorting to actually removing the sim cards.