Our numbers are getting banned all time time. using yowsup. This is NOT due to spam! Whatsapp recognizes yowsup as an unauthorized application. At this point, we cannot use yowsup anymore without getting banned sooner or later. How can we solve this?

Whatsapp worte:

Thanks for your message.
Your WhatsApp account was banned because you violated our Terms of Service and were using an unauthorized application and/or unsupported device.
Please uninstall your application and install an authorized version on supported devices from:
www.whatsapp.com/download
Please note that we do not allow use of unofficial clients or jailbroken/rooted (including emulators), and unsupported devices.
To use WhatsApp on your computer, access our website from your computer’s browser. Then, open the app and scan the QR code using the WhatsApp app on your phone (look for WhatsApp Web menu under Settings). WhatsApp can only be installed on your computer if your operating system is Windows 8 (or newer) or Mac OSX 10.9 (or newer). If you are having issues installing WhatsApp on a supported operating system, turn off your anti-virus and try again.
For all other operating systems, you may use WhatsApp on your browser here
Your account will be permanently banned if you continue to violate our Terms of Service, and there will be no possibility of an appeal.
Best Regards,