Fairycakes
We don't answer the house phone at all any more due to the number of nuisance calls we were receiving, but I still get them on my mobile. I have only given my mobile number to family, doctor, dentist, hospital, so have no idea how these companies know my number 🤔
Chances are they DON'T know your number, Fairycakes, any more than the people who use the postman to deliver flyers to every house in the area, with unmissable offers on paving, pizzas and polythene greenhouses. They can get automatic programs that are dialling the next number while you are answering the last one. That is why it is worth taking advantage of any option your phone provider has to block numbers that are known to be a nuisance, or getting your number onto the Telephone Preference Service, where organisations doing telemarketing have to check at least every 28 days that the numbers they are phoning have not opted out of reciving unsolicited sales and marketing calls.