Security risk concern

I have called ABSA and been to a branch to stop receiving someone else's notifications on my cellphone number. But nobody seems to be too concerned. Wonder if anyone is also getting my banking notifications. Nobody at ABSA seems to feel that it is a security risk. Unfortunately I am a bit paranoid since I had to report identity theft to the police and TransUnion before on my profile. I would feel immensely better if someone actually worried about security risks at ABSA. The other person's notifications has been coming through to my number for quite a number of months now. The other concern I have is, if you do manage to fix this problem, will I still get my notifications or will it change into a different problem?