If you have an iPhone with the latest version of iOS, there is a wonderful little setting on the phone that will send those unwanted scam and robocallers directly to voicemail.
You can find the setting in your Settings app, and under Phone, look for “Silence Unknown Callers”. This will allow your legit callers to reach you, but if an unknown caller is trying to call you, it will go directly to voicemail.
Here is a screenshot from my phone where the setting is..
If you are not sure if you have the setting on your phone, check with one of your family members.