Unfortunately, spammers of any kind are difficult to deal with and often the best you can hope for is to discourage them enough they move on to someone else for while. We deal with them here in community frequently. GoTo Connect has a suspected SPAM label, but it only appears if the number calling is already on an FCC list that we check. The call filters can also help, but when they can easily change numbers it is more challenging. I would recommend trying mkeaton's suggestion, my phone has a similar feature for calls from unknown numbers and they always hang up.