OptOut of marketing FOR-E-VER!!! PLEASE!!!!

Y'ello! Here is your annoying message from MTN to which you haven't subscribed. To OptOut SMS STOP to 30246.

Why do you give this option to optout of something Ive not opted in for, yet don't honor an OptOut request?

I've sent too many of these opt-me-out-please messages, the last ones were 10 Feb and 3 April. It would seem to work for a little while, then bam, here are our sms's again.

Please MTN. Unsubscribe me... my number is ... wait, you have it.