Harassment by MTN telemarketing

I am HARASSED by the MTN telemarketing team on a daily basis, multiple times a day. Despite me blocking the numbers each time, they continue to generate new numbers to harass me. I've also lodged a formal complaint with MTN regarding this, indicating this harassment, and requested being added to the Do Not Call list. I've received a response from their complaints team, apologising and indicating they've added me to the Do Not Call list. Notwithstanding this, I am still continuously being harassed, even way past their "window period" for processing this request.

They've either been dishonest about adding me to that list, or there is a failure of controls to monitor these ******* practices.

How is it legal/permitted for these companies to generate infinite numbers to perform these ******* practices despite requesting them to stop? What is the purpose of the complaints department in such instances? Why is there such poor/ineffective regulation and governance regarding these ******* practices? I'm pretty sure there's contravention of a number of pieces of legislation, yet they continue. I am surely not the only person experiencing this. This ******* practice is an absolute nuisance, disrupting my work; causing me frustration and even disturbing me after business hours.

I'm reaching out because the internal channels that are supposed to be addressing this, are condoning/facilitating such practices, and there seems to be no repercussions.