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.
I did report it to the Police, not because I was worried - they were after card details to get money. They'd never bother to visit me, do violence all for no profit ... But I felt given the nature of the threats the Police should know/log or whatever they wanted to do.
The retailers were major manufacturers one makes at least half the computer disk drives in the world so not dodgy operators.
2FA would not have helped much - my cards use OTP to my mobile number ie max. the Visa cards provide and the SCAMers know exactly what transactions will ignore this requirement. Each instance they got between £1000-2000 but on small transactions to eg supermarkets, Wayfair (one I remember) all close around £100 but they knew exactly what transactions would not be sending me a OTP code ie I never got any 2FA messages. Card company refunded the transactions without question - took a bit of time on the phone going through each transaction "Was this you?" and I answer Yes or No and they immediately refund those I said Yes to (no questions).
I'd always thought that online retailers validate the CVV code and are not allowed to store it but apparently (card company said) it's up to the retailer if they store the CVV and that these two mainstream reputable retailers did store it and thus hackers got it.
