How to stop spam calls and texts for an American SIM?

I've recently moved to America and set up my first SIM card. I now get 2-10 phishing texts or scam calls a day while while the help desk at the telecom pretty much says, "that's just the way it is".

Has anyone had any success greatly reducing this? I'm seriously considering disabling SMS and calls on my mobile and having a home phone connected to an answering machine.