I changed my ID sim deal to another one still with ID on my Samsung S8 and asked to keep my number, all went well for a couple of months, then after a few weeks the family told me the number had changed when I called them ? Not sure why as the original phone number worked fine and still appears on my online ID account as the phone number allocated to the phone ?
I need this to be sorted as all friends and family know my original number and this is a real inconvenience at the moment.