T-Mobile Twist SIM CARD has got ROAMING activated that means you can use it abroad of Czech Republic (phone calls, txt, data)

If SIM CARD hasn't  got signal in the phone that means you need to activate it through T-Mobile CENTRUM in Czech Republic by calling phone number in the back of SIM CARD and give operator details of your received SIM CARD.

Yours SIM CARD should have full services up and running afterwards.

You may need to restart your phone fo rservices.