Well that's what the US is trying to do about it – what's happening in the UK? I get robocalls quite often, both on landline and mobile, and I'm baffled as to (a) why something isn't being done about it and (b) who TF believes a robot telling them their card has been declined for Amazon Prime or that they're under investigation by HMRC‽ Depressingly, because they keep on trying it, I'm guessing that the answer is "at least enough people". Sigh.