First of all, we fully appreciate your referral.
Please kindly note that three conditions need to be satisfied in order to get the 20 Credits REWARD:
1. There're several entrances to send invitations, the valid entrances are 'More->Get Free Credits >Earn 20 credits for each friend you invite'. Besides, you can also invite your friends through the entrance after Checkin or finishing a call. Which shows "Earn 20 credits for..." is valid.
2. Your friend's device has never installed Dingtone.
3. Your friend needs to finish the process of clicking the link in the invitation message, downloading the application and registering with phone number/email/Facebook as a Dingtone user.
If you still didn't receive credits with all conditions met, please share the invitee's Dingtone ID with Dingtone support.