That's a shame! Now the next rider won't be able to find the bike where it's supposed to be.
If it's really impossible for you to return the bike to its pick up location, make sure you still lock it and click END RENTAL in the app. Then please send us an email with the address where you left the bike. A screenshot with a pin on Google Maps would also help us a lot.
Keep in mind that if you end the rental outside the original hub, you will be charged a relocation fee. Here is a list of the fees.