From the home screen you must enter a series of numbers and symbols. it is different for every SIM card, you MUST call customer or technical care to get what is called the PUK (Pin Unblocking Code). if you enter in the wrong PUK a number of times, the phone will automatically destroy the SIM card. whatever you do, do not try a code that someone other than T-Mobile gives you.
When your phone says that it happens because of security being set up on the phone or an attempt to set up security and not knowing the password...
if the password is incorrectly entered a number of times then it will completely lock up the phone having you call customer care to verify that its you that has the phone...
they have a special password they can give you to get that phone unlocked again

Hi there,

Is the password was a Security password, or the PIN/SIM password?

Regarding with your problem, you better call your network provider for this issue, they can assist you and remotely unlock your phone.

Hope this initial info helps.

micro~