Number does not exist and Spam popup

2 issues: Issue 1: after EVERY-SINGLE-CALL a population appears informing me that I will receive 0% discount. Thank you MTN for this very informative and not annoying at all pop-up.

Issue 2: when I don't answer my phone, it does not divert to voicemail. Instead, a lovely, very official MTN voice starts talking, and informs the caller that the number they dialed does not exist. So basically my number does not exist. This is of course JUST FANTASTIC FOR BUSINESS (I am on a MTN business contract)

I have spent hours on the phone with the MTN call centre. They cannot fix the issues. I have gone in to the MTN shop in Woodlands, and they too cannot help me.

I am super disgusted. What am I supposed do do?