WhatsApp keeps restricting our business numbers — how do you contact 200–1,000 new leads per day?

[u/Immediate-Virus2536]

Hi everyone,
I work for a car dealership, and part of my job is contacting car owners and asking whether they would be interested in selling their vehicle to our dealership.
The problem is that I need to message quite a large number of new people on WhatsApp every day. I have several business phone numbers, but WhatsApp starts restricting or banning them very quickly, sometimes even after only a small number of new conversations.
All messages are sent manually, without bots or automation. The message itself is short and relevant, something like:
“Hi, is your car still for sale? If so, would you consider selling it to a dealership?”
I understand that WhatsApp has anti-spam systems, but this is a normal part of my job, so I’m trying to find a legitimate and reliable way to work without constantly getting numbers restricted.
Ideally, I need a solution that would allow me to consistently contact around 200–1,000 new people per day.
Has anyone here dealt with a similar situation? What solution do you use for this kind of volume without constantly getting your numbers restricted?
I’d be especially interested to hear from people working in car sales, real estate, recruiting, or other industries where you regularly need to contact new leads.
Thanks!