No opt-out for spam SMS and broken systems everywhere

Continues to spam me despite me opting out of every option I can find. Each SMS teases that I can opt out by dialing *135# but there is no longer an option to opt out anywhere in that quagmire of an of outdated system (who still uses USSD besides MTN? Not only is the system archaic but it is broken. Many of the menu options lead to dead ends. The MTN menu that im forced to install on my device is similarly broken and poorly designed. Stop spamming me and directing me to what turns out to be a blatant lie