The carrier, no matter who it is, isn't going block calls without the user telling them which ones to block, or actively opting into a service (app) that gives them permission to block calls that they deem as spam or risky. Think of the quagmire that would ensue if they proactively blocked calls to consumers that they unilaterally decide the consumer doesn't want to get. Users would be upset because that call that the carrier thought was spam was someone that they actually wanted to talk to. Businesses can sue for blocking access to their customers.
So, the way for the consumer to tell the carrier which calls to block is through any variety of apps that are unfortunately only available on Smartphones. In 2019, it is projected that half of all calls that traverse mobile carriers' networks will be robo/spam calls. The popular smartphone operating systems come with the ability to select a call and add it to a block list manually. In addition to that, AT&T (as an example) has an app called "AT&T Call Protect." They actively classify spam, telemarketers, etc. When a call comes through it will say "Suspected Spam" or "Telemarketer" or "Potential Fraud" You can also block these types of calls through the app.
Someone calls me dozens of times a day from a 908 number but I never see them - they're actively blocked by the AT&T app. The robocaller is so fast that it redials within milliseconds as soon as the call is rejected. Most calls come up 10 or more times in a row and all appear to be at the same exact time because it dials back so fast.
Might be time to get a smartphone...