You would think that in this day in age there would be some way networks can block these calls
You can block specific numbers yourself on your own device if you want to stop the calls.
Given the variety of numbers they seem to be using for this and similar scams, you may have to do it for more than one number. This also indicates how difficult the job would be for the network operator to do automatically, after all, it's just another phone number on their network until and unless someone reports suspicious activity associated with it
The scammers use auto-diallers, they used to be electro mechanical devices but are now software based, generating and dialling numbers at incredible rates until they get an answer, which is then recorded automatically, as are the credit card/bank account details for immediate use and later re-use, if they are revealed. The fact that they got an answer from your phone may mean your number gets passed on to another outfit via the "scammers' phonebook", whether you buy or not from the first caller.
From the Home screen tap "Settings" then "Phone" then "Blocked Contacts".
Add the phone numbers to the list of Blocked Contacts. The specifics will vary between iOS and Android or other phone OSs. You won't receive calls, texts, emails, Facetimes, etc. from any of the listed numbers until you unblock or unlist them. My phone is also set to reject any calls from private numbers, i.e. phones which withhold their caller ids, which can keep the Bible and aluminium window salesmen at bay.
You can of course also set your phone to reject all calls from numbers that do not appear in your contacts/phone-book. This may be a bit extreme but then again it might suit some users..
