Cleeng has a way for you to check how many customer's bought your offer. Here's a simple guide on how to do that:
1. Go to 'Offers sales' tab under the 'Reporting' section where you will see all your offers listed.
Here you have a search option - search by date and type of offer and/or its ID.
2. Click the 'list' icon - see below - this will reveal all customer transactions for this offer.
3. From here you can go even deeper in all details of this particular transaction, resend a receipt or cancel and refund this transaction.
For any other questions please contact the Cleeng Support team via https://support.cleeng.com/hc/en-us/requests/new for further help.