Почему не сохраняет SharedPreferences?

Сохраняет только один раз, потом не прибавляется к переменной вообще

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initialize();
        initializeLogic();
        if(data.getString("money", "").equals("")) {
            data.edit().putString("money", "0").commit();
        }
        else {
            textview3.setText(data.getString("money", ""));
        }
    }
    private void initialize() {
        button3 = findViewById(R.id.button3);
        button2 = findViewById(R.id.button2);
        button1 = findViewById(R.id.button1);
        linear1 = findViewById(R.id.linear1);
        textview2 = findViewById(R.id.textview2);
        textview3 = findViewById(R.id.textview3);
        data = getSharedPreferences("IOExceptionMiningFer", Activity.MODE_PRIVATE);
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                RewardShow();

            }
        });
    }
    public void initializeLogic() {
        MobileAds.initialize(MainActivity.this, new OnInitializationCompleteListener() {
            @Override
            public void onInitializationComplete(InitializationStatus initializationStatus) {
            }
        });
        RewardLoad();
    }
    public void RewardLoad() {
        AdRequest adRequest = new AdRequest.Builder().build();

        RewardedAd.load(this, "ca-app-pub-3940256099942544/5224354917",
                adRequest, new RewardedAdLoadCallback() {
                    @Override
                    public void onAdFailedToLoad(@NonNull LoadAdError loadAdError) {
                        // Handle the error.
                        mRewardedAd = null;
                    }

                    @Override
                    public void onAdLoaded(@NonNull RewardedAd rewardedAd) {
                        mRewardedAd = rewardedAd;
                    }
                });
    }
    public void RewardShow() {
        if (mRewardedAd != null) {
            Activity activityContext = MainActivity.this;
            mRewardedAd.show(activityContext, new OnUserEarnedRewardListener() {
                @Override
                public void onUserEarnedReward(@NonNull RewardItem rewardItem) {
                    // Handle the reward.
                    btc += 2;
                    data.edit().putString("money", String.valueOf((long)(btc))).commit();

                    int rewardAmount = rewardItem.getAmount();
                    String rewardType = rewardItem.getType();
                }
            });
        } else {
        }
    }

}