If you’re dissatisfied with TickTick, you can apply for a refund within 14 days after purchase.
Paid with Google Wallet:
1. Open the Google Play Store app and sign in;
2. Touch the Menu icon > My Apps > Subscriptions or search TickTick directly in Play Store;
3. Select TickTick to view its detail page > Cancel your monthly/Yearly subcription;
4. Tap on YES to confirm your choice.
Paid with Paypal:
Send your Paypal Account and Transaction ID at firstname.lastname@example.org and your refund request will be processed within 3 business days.
Hope this may help you smoothly get the refund.