How long is going to take facebook to electify this?why would one similar mobile phone number be used to login to more than 2 different facebook accounts?

How long is phone number supposed to apend before it gets discovered that it's associated qith another's account????as you see in the pictures, 0789407795 can be used to login to more than two different accounts.. If facebook sends you a code to confirm a number ,just do not enter the code and the number will be kept pending but will be used as a login id to another different account evwn if it may be belonging and confirmed with another account.. Now ,look at the phone number 0706898585,Facebook gets to know that its associated wih another account but does nothing from prohibiting it to be a login id to another account