That’s wisdom I think. Especially not allowing credit card details to be held. It’s only a few moments extra to add that information each time.
I’m not sure what to say about the phone scam attempts. My approach - which seems to bear dividends - is to allow them to chat to my answering machine for as long as they like. That goes towards their call costs and overhead time, which they won’t like and will avoid. A phone answered is a phone with someone on the other end to be called again later. All unrecognised numbers are left unanswered this way, but you need a system with plenty of call/numbers memory.