Uncalled for advertising

Dear MTN, What on earth gives you the right to send an advertising sms to me late at night - 22h57 last evening, or any other time for that matter. This as an absolute cheek. Please respect my privacy, just because I use your service does not give you any right to send your junk to me. I direct that you delete me from all and any junk mail sendings and that you respect my privacy. Ted.