Reclycling old cellphone numbers

My phone was ****** a year ago and I blocked the number however I have just received an email with someone from a company trying to assist me with accessing my account details. It was very confusing as I did not sign up for Binary Options. This person told me that someone from my old number is trying to buy something online and my email address came up. This is extremely dangerous when Vodacom reclycles your old number as you are not able to notify everyone that you have ever dealt with to inform them that your phone has been ******. Apparently the person who is using my old number has had calls from companies asking for me, so there is no way that you are able to inform everyone that your phone has been ******. Why not create a new number instead of reclycling it?? You use your number for everything these days (accounts, etc.) and this is so dangerous when someone else will be able to have access to these things. Stop reclycling numbers, it is dangerous!!!