I keep getting nuisance calls from the UK. These are auto dialed and only sometimes is anyone on the other end.
Yes you can block numbers on your mobile. How effective it is , is another question as most of these a-holes change numbers frequently.
Not sure if your using Apple or Android so two links below that can explain it.
Also there are Apps (both on Apple Store or Google Play) that can block these calls as well. Most would be paid apps but they check against a database of known spammers.
Upon checking I did indeed find that the numbers are all a bit different and there is no reason not to think that future calls will be different again. Oh well, back to being abusive!