Here are a few conditions to receive credits for a task:
1. This is the first time you download this particular app to your device.
2. You opened the app and used it for at least one minute.
3. You have not switched networks during the process, e.g. 3G to WiFi.
Make sure you follow these steps and with a little patience you'll receive your credits within 24 hours.
Usually, when you do not receive credits, we do not get paid either. Unfortunately, sometimes some of our providers' offers may not convert. We have been helping users in these cases just as to make their experience better. However, normally we are not authorized to do that because as mentioned above it is a loss for us to give credits when we are actually not getting paid.
The best converting offers are always on the top of the list of your offer wall. Make sure that you download those first.
Tip: If push notifications are enabled for AppBounty, try to use the app until you receive a message that you received your credits.
If you tried to invite a friend make sure your invitee used your invite code while signing up to AppBounty. If you friend only downloaded BountyBucks and no further offer this might also be a reason why you did not receive your credits.