Go to the official website of mobile operator Kyivstar - Next at the bottom of the menu find the item "My Kyivstar" (for example, in the MTS this section of the website called "Internet assistant"). As a login in the system "My Kyivstar" is the number in the format +380ХХХХХХХХХ and the password will be sent immediately after registration.
In order to obtain a password and become a member of the system, click the menu item "Registration" (this process is individual for each operator of cellular communication). Next page will load where you will be asked to enter your subscriber number and send the request with the *100*88*the numbers shown on the picture #, after which you will have the answer.
Then click on the button "Register". You should receive an SMS message, which will contain a username and password to log in to the system "My Kyivstar". The password is valid only 2 days, so change it immediately. To do this, log in to the website by entering the received login and password, go to the "Profile" section, click "Edit" and select "Edit password." You are now logged in and can view your incoming and outgoing calls on your number.
Navigate to "Expenses" and select "Calls". You will see a list of calls (date, time, number, duration of conversation and its final cost), also at the end of the list shows the amount of money spent for the month. List is generated for the previous month and not current. Enjoy!