^What that guy said. *waves hello to the fellow Okie*
The only thing I might add on the specific subject of robocalls is that the pool of available phone numbers is pretty fixed, and number turnover has increased over the years - especially with the expansion in popularity of disposable numbers, VoIP in general, the internet of things being wired through the mobile network, and the decreasing overall time that used phone numbers are being left out of the reactivation pool before being pressed back into service. As such, there's no guarantee that a number change will actually improve the situation. I've been getting more junk calls lately myself. A lot of others have, too. The only way to fight it, unless your carrier allows you to do phone number whitelisting (no mobile carrier that I know of does that), is through FCC complaints and smartphone call screening software such as Mr. Number (which datamines you just to filter others out) if your phone doesn't give you the option to whitelist in the OS itself (as far as I'm aware, that's still something I think only Windows Phone does currently - but anyone please correct me if I'm wrong).
As for phones, for utilitarian workhorses that aren't used for excessive social networking and as entertainment devices, again, Windows Phones are good, especially used for the money. A used Lumia 640 can be picked up carrier unlocked in good condition for around $50-75. Still has long term Windows 10 support on it, you can replace the battery yourself, and most everyone I've recommend one to has liked the thing.
