As long as you follow the WhatsApp terms of service, particularly the parts under "Acceptable use of our services" then I'm sure you won't get banned for spam.
I've been sending messages to the WhatsApp sandbox as part of the Twilio API to test my application and had no problem.
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
As long as you follow the WhatsApp terms of service, particularly the parts under "Acceptable use of our services" then I'm sure you won't get banned for spam.
I've been sending messages to the WhatsApp sandbox as part of the Twilio API to test my application and had no problem.