Yeah I liked that strategy you had, keeping the old one for even a month or two to get things swapped over before cutting it.
My wife gets far more spam calls than I do, she gets them multiple times per day. I am much more restricted with where I give my number and I think that's helped. She signs up for every fucking reward program under the sun lol
My problem was that my old number was the one I used for work for many years and that meant years of spammers and scammers like Nigerian Princes knowing it. I don't know how many times I was declared the sole heir to a billion dollars or a castle estate in fucken Scotland...Anyway, so far I've had none on my new number. I'm sure they'll find me though.