We apologize for the inconvenience. You can remove them free of charge by restoring your purchase.
Tap "Restore removed ads" in the Settings screen.
In rare cases this does not work. If so, please run the purchase process again.
As long as you use the same Google Account, you will never be charged twice, so please rest assured.
If it still does not work, please contact us with the details using the "Contact us" button at the top right.