Maybe you have registered elsewhere, such as buying a car or a house. In short, your number is leaked. Do not register a 2 1 century system. Can't find the external network. It's their intranet, and then no matter which franchise store finds your information in 2 1 century, it will call you.
Call again next time. You ask them to write in the message that there is no house for sale, which is false information. Their salesman will not call you if he can see it in the system.
I hope this helps.