Contact your mobile operator. For example, visit the office of maintenance. There with the help employee write a statement in the prescribed form for the loss of your phone. You will ask passport data, so I take identity documents with them.
In addition, if you are an irretrievable loss of the cell, can be directly in the cabin to write a statement about the recovery of lost SIM card to arrive for this additionally. However, the new SIM card, although it will have the same phone number, but will receive a different pin code that you need to pay attention.
You can also block your number and taking advantage of people's mobile phone. Call in help mobile operator and lock a lost device by phone - however, in this case, you need to have a passport or remember all the data in this memory. This call is free of charge to all cellular companies.
If you registered as a user on the website of your service provider, then log in to "my account" and fill out the form on the phone lock. Your request will be processed immediately.
Mobile operators present, and the service temporarily block numbers. For example, if you are away on vacation or on a long trip to another country. In this case, lock the room to avoid paying the monthly fee, for a period of up to six months, but this service is on a paid basis.
You can hold and block unwanted incoming numbers, if the phone can activate the "black list" that depends on the model and operator. Log in to the phone menu and tick the numbers of unwanted callers, agree with the proposal to move them to the blacklist. If you could not do, make a list of those phones that you wish to block and send SMS to the service number of your provider. Check beforehand the cost of this service.