On two occasions an online purchase (very reputable retailer) has been hacked and hackers got my details and whilst I was fully refunded their use of my card (between £1000-2000 both times), the real grief came from the 2nd hack where they started texting me with rather easy to detect SCAMs. They when I didn't respond they started calling me pretending to be my bank maybe once a week. When calls didn't work they started calling me with threats ending up with "Your address is <xyz> and we're going to come round any <sexual violence> your daughter ..." 9which of course they wouldn't 'cos they just want your money. But I then decided time to change number and it's real grief with all the OTPs from all sorts of official bodies, some of which make changing your number more than difficult.
Sounds awful. I've never had an issue and have had the same mobile phone number since 1993.
Presumably you reported the calls to the Police? These days I just block scam calls - android is very good at highlighting possible scam callers. It's very hard to steal my money without the 2FA verification, and without the bank spotting misuse pretty damn quickly. I'm not saying it's impossible, just that (touch wood) it's never happened to me.
To be fair, I only use Whatsapp for personal communications (family, friends etc). It has never bothered me that Meta have all my data as Alphabet have it all as well. They know exactly where and when I have been for the last 10 years, most of my email and all of my photos live in Google's cloud.