Absa annexed my phone!

Getting bombarded with marketing without being to able to unsubscribe. Getting constant emails, SMS's, and app notifications. After mailing them, they instructed me to change my marketing preferences on the app which I did (and to which I never consented btw), but the spam continues. They then informed me to go to a branch. My phone is busy as it is, but productively so - I cannot entertain forced, unwanted communication.