ADT sells cell phone numbers to marketing agents

For the last few years I've been inundated by calls and sms's from marketing agents trying to sell products. I'm sure you've all had similar experiences so I'm not alone. What you don't perhaps know is how these agents get your name and number. Well, I have proof that my security company (ADT) sold my details to agents. I took over control of a beach cottage on the kzn south coast from my brother in law and I contacted the local ADT branch and asked them to change the cell phone number they had on their data base which they use in case they need to contact anyone in the event of a alarm activation at the premises they monitor. However, I did not change the name of my brother in law that they had on the data base so in essence they had my cell phone number and my brother in law's name on their data base. As I have never had much to do with my brother in law in the past, there is absolutely no way possible that my cell number and my brother in law's name can be associated other than on ADT's data base. I've been getting calls and sms's for the last few years addressing me by my brother in law's name????This is therefore proof positive that ADT sold the details. ***** or what????