Who called from 2535617900

I keep getting calls from this number, but no message is left.

I do not recognize number but name said Steph Powers

who is this person

I called the number back pressed the option to be put on Do Not Call List-----Its a marketing company

What number on the keypad do u punch to put the annoying #'s on a do not call...do you do that from your keypad or is there a way only when you call the number back.