Some of these sales calls do come from abroad, and many are pre-recorded messages. Probably that`s why your personal alarm does not deter them.
You could speak to BT, but I doubt they could stop nuisance calls coming from abroad.
The Evil Within 2 review-in-progress
Adobe shows still-in-development tools, including automatically colourising black-and-white photos
iPhone X news: Release date, price, new features & specs
Comment transformer un iPhone en borne Wi-Fi ?