my phone was stolen last day and its switched off now , is there any way to get my contacts back? my phone was stolen last day and its switched off now , is there any way to get my contacts back ? There is a screen lock with numbers, can anyone access the phone without formatting the phone . If they format all the datas will be lost right? And als can I block my memmory card by an means ?
If you have your phone linked to your Google account, your contacts are, by default, saved to your Google account, and you can access them through gmail. Even better, if you get a new phone and link it to the same account, it'll have all your contacts again. 
If it is linked and your phone is turned on you can find it's location through Google's Device Manager or remotely wipe your phone. 

Keep in mind that if it's linked and they manage to get in somehow, they'll be able to access your Google account as well, so if you don't intend to locate the device you should unlink your device from your Google account, blocking their access to your account. 

Unfortunately, if your device is not linked, or you chose to save contacts locally instead of the default location, there's no way of getting your contacts back, unless your manufacturer offers a way for it and you have enabled it. I believe HTC has something for it if you link your HTC account.