I can confirm the giving out of private numbers is a grave mistake. Years ago I gave out my private number and was stalked for months by Nigerians (could tell by the distinctive accent) saying that I owed money as the money I had paid with was false. I was shocked when I discovered where they had found my number as only one lady had my private number and it turns out she was threatened with her life and eventually gave in to the pressure. It’s easy to say just ignore them, they have means. These days I use a burner phone that doesn’t even have WhatsApp on it. No more hassles.