Private boolean cannot recognize return in "if statement"

My code:

import javafx.event.ActionEvent;
import javafx.scene.control.Label;

import java.util.Arrays;
import java.util.Random;

public class Controller {
    public Label keno;
    public Label loto;
    public Random rd = new Random();

    public void click(ActionEvent actionEvent) {

        String pom = "";
        int[] ken = zrebuj(10, 80);
        pom = Arrays.toString(ken);
        pom = pom.substring(1, pom.length() - 1);
        keno.setText(pom);


        ken = zrebuj(5, 35);
        pom = Arrays.toString(ken);
        pom = pom.substring(1, pom.length() - 1);
        loto.setText(pom);
    }

    private int[] zrebuj(int pocet, int max) {

        int[] cisla = new int[pocet];

        for (int i = 0; i < cisla.length; i++) {
            int tah = rd.nextInt(max) + 1;

            if (jeTam(cisla, tah)==false) {
                cisla[i] = tah;
            }
            else i--;
        }
        Arrays.sort(cisla);
        return cisla;
    }

    private boolean jeTam(int[] cisla, int tah) {

        for (int i = 0; i < cisla.length; i++) {

            if (cisla[i] == tah) {
                return true;
            }
            else return false;
        }

    }
} 

My problem is, that when I start program, it crashes and it says: "Missing return statement" at the private boolean, even thought it´s right there in if statement.

Could you help me please? Thanks!

*Also, if you have any tips to make it better, just tell me in the coments ;)