Zte Telstra Qwerty-Touch User Manual page 92

If you forget the unlock pattern then after five attempts you can
enter your Google account details to unlock your device. If you
have not registered a Google account then contact your service
provider.
SIM Card Lock
Set a PIN code on your SIM card to prevent others from using
your account. The initial PIN code is provided by your service
operator.
1. Tap Home > Menu > Settings > Location & security >
Set up SIM card lock.
2. Select Lock SIM card. Enter the PIN and tap OK.