Previously anyone with an account could get free Whatsapp usage worldwide after they reload credit for the first time. Credit didn't use to expire so one could theoretically have had free whatsapp indefinitely.
Now they are restricting free Whatsapp use to 30 days max after every top up. Also credit expires after 9 months unless you top up - then it rolls over indefinitely.
Probably abused and makes sense not to offer it without any restrictions. I never used made use of it personally but I have a knowroaming sim.
"In order to continue offering our bonus WhatsApp promotion to our growing customer base, we have updated the eligibility requirements. This promotion is designed as a bonus for active customers using KnowRoaming services and will no longer be available for customers who have not loaded credit onto their account.
At this time, your account does not meet the eligibility requirements, so you will not be able to access this promotion. In order to qualify for this promotion, you can simply load credit onto your account in the KnowRoaming app by selecting “Tap to Reload” and following the prompts. Once you have loaded credit onto your account, this promotion will automatically reactivate within 48 hours. Following this, you will be able to enjoy 30 days of free bonus WhatsApp usage each time you load credit. Read full details here.
Your account credit can be used for data and voice services. In addition to our per MB data rates, we offer a range of unlimited and fixed data packages designed to suit your needs. Please find all the available packages in the KnowRoaming app > Services > Packages.
If you have any questions, our 24/7 Support Team is always happy to help at email@example.com or a number that is local to you."